[pylint] Detect invalid default value type for os.environ.get (PLW1508) (#16674)

## Summary
This PR stabilizes the new behavior introduced in
#14512 to also detect defalut
value arguemnts to `os.environ.get` that have an invalid type (not
`str`).
There's an upstream issue for this behavior change
pylint-dev/pylint#10092 that was accepted and
a PR, but it hasn't been merged yet.

This behavior change was first shipped with Ruff 0.8.1 (Nov 22). 

There has only be one PR since the new behavior was introduced but it
was unrelated to the scope increase
(#14841).

Author: MichaReiser

crates/ruff_linter/src/rules/pylint/mod.rs

@@ -445,7 +445,6 @@ mod tests {
         Rule::RepeatedEqualityComparison,
         Path::new("repeated_equality_comparison.py")
     )]
-    #[test_case(Rule::InvalidEnvvarDefault, Path::new("invalid_envvar_default.py"))]
     #[test_case(Rule::BadStrStripCall, Path::new("bad_str_strip_call.py"))]
     #[test_case(
         Rule::BadStaticmethodArgument,

crates/ruff_linter/src/rules/pylint/rules/invalid_envvar_default.rs

@@ -52,14 +52,10 @@ pub(crate) fn invalid_envvar_default(checker: &Checker, call: &ast::ExprCall) {
         .semantic()
         .resolve_qualified_name(&call.func)
         .is_some_and(|qualified_name| {
-            if checker.settings.preview.is_enabled() {
-                matches!(
-                    qualified_name.segments(),
-                    ["os", "getenv"] | ["os", "environ", "get"]
-                )
-            } else {
-                matches!(qualified_name.segments(), ["os", "getenv"])
-            }
+            matches!(
+                qualified_name.segments(),
+                ["os", "getenv"] | ["os", "environ", "get"]
+            )
         })
     {
         // Find the `default` argument, if it exists.

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLW1508_invalid_envvar_default.py.snap

@@ -50,3 +50,13 @@ invalid_envvar_default.py:14:17: PLW1508 Invalid type for environment variable d
 15 | os.environ.get("TEST", 12)  # [invalid-envvar-default]
 16 | os.environ.get("TEST", "AA" * 12)
    |
+
+invalid_envvar_default.py:15:24: PLW1508 Invalid type for environment variable default; expected `str` or `None`
+   |
+13 | os.getenv("AA", "GOOD" if Z else "BAR")
+14 | os.getenv("AA", 1 if Z else "BAR")  # [invalid-envvar-default]
+15 | os.environ.get("TEST", 12)  # [invalid-envvar-default]
+   |                        ^^ PLW1508
+16 | os.environ.get("TEST", "AA" * 12)
+17 | os.environ.get("TEST", 13 * "AA")
+   |