[pigeon] Reduces lint rules ignored in generated Dart code (#11230)

When I landed #11149, which
changes the `ignore_for_file` to use `type=lint`, I didn't examine the
list of lint rules we _used to_ violate. In particular, since
#11114 and
#11163 landed, our generated
code no longer violates the following rules:

* unnecessary_parenthesis
* prefer_null_aware_operators
* unnecessary_import
* no_leading_underscores_for_local_identifiers

I believe this does not need CHANGELOG notes because users should not be
using the _hidden_ 'ignore-lints' flag. This list of individually
ignored lint rules should only appear in our tests or our checked-in
generated Dart files.

## Pre-Review Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [AI contribution guidelines] and understand my
responsibilities, or I am not using AI tools.
- [ ] I read the [Tree Hygiene] page, which explains my
responsibilities.
- [x] I read and followed the [relevant style guides] and ran [the
auto-formatter].
- [x] I signed the [CLA].
- [x] The title of the PR starts with the name of the package surrounded
by square brackets, e.g. `[shared_preferences]`
- [ ] I [linked to at least one issue that this PR fixes] in the
description above.
- [x] I followed [the version and CHANGELOG instructions], using
[semantic versioning] and the [repository CHANGELOG style], or I have
commented below to indicate which documented exception this PR falls
under[^1].
- [ ] I updated/added any relevant documentation (doc comments with
`///`).
- [x] I added new tests to check the change I am making, or I have
commented below to indicate which [test exemption] this PR falls
under[^1].
- [x] All existing and new tests are passing.

Co-authored-by: stuartmorgan-g <stuartmorgan@google.com>

Author: srawlins

packages/pigeon/example/app/lib/src/event_channel_messages.g.dart

@@ -4,7 +4,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/example/app/lib/src/messages.g.dart

@@ -4,7 +4,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/lib/src/dart/dart_generator.dart

@@ -159,10 +159,8 @@ class DartGenerator extends StructuredGenerator<InternalDartOptions> {
       // in our own checked-in generated files.
       indent.writeln(
         '// ignore_for_file: public_member_api_docs, '
-        'non_constant_identifier_names, avoid_as, unnecessary_parenthesis, '
-        'prefer_null_aware_operators, omit_local_variable_types, '
-        'omit_obvious_local_variable_types, unnecessary_import, '
-        'no_leading_underscores_for_local_identifiers',
+        'non_constant_identifier_names, avoid_as, omit_local_variable_types, '
+        'omit_obvious_local_variable_types',
       );
     }
     indent.newln();

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/core_tests.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/enum.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/event_channel_tests.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/event_channel_without_classes_tests.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/flutter_unittests.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/message.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;

packages/pigeon/platform_tests/shared_test_plugin_code/lib/src/generated/multiple_arity.gen.dart

@@ -5,7 +5,7 @@
 // Autogenerated from Pigeon, do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: unused_import, unused_shown_name
-// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, omit_obvious_local_variable_types, unnecessary_import, no_leading_underscores_for_local_identifiers
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, omit_local_variable_types, omit_obvious_local_variable_types
 
 import 'dart:async';
 import 'dart:typed_data' show Float64List, Int32List, Int64List;