[flake8-simplify] Stabilize split-static-string (SIM905) (#16631)

Summary
--

Stabilizes SIM905 and adds a small addition to the docs. The test was
already in the right place.

Test Plan
--

No issues except 2 recent, general issues about whitespace
normalization.

Author: ntBre

crates/ruff_linter/src/codes.rs

@@ -489,7 +489,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Flake8Simplify, "223") => (RuleGroup::Stable, rules::flake8_simplify::rules::ExprAndFalse),
         (Flake8Simplify, "300") => (RuleGroup::Stable, rules::flake8_simplify::rules::YodaConditions),
         (Flake8Simplify, "401") => (RuleGroup::Stable, rules::flake8_simplify::rules::IfElseBlockInsteadOfDictGet),
-        (Flake8Simplify, "905") => (RuleGroup::Preview, rules::flake8_simplify::rules::SplitStaticString),
+        (Flake8Simplify, "905") => (RuleGroup::Stable, rules::flake8_simplify::rules::SplitStaticString),
         (Flake8Simplify, "910") => (RuleGroup::Stable, rules::flake8_simplify::rules::DictGetWithNoneDefault),
         (Flake8Simplify, "911") => (RuleGroup::Stable, rules::flake8_simplify::rules::ZipDictKeysAndValues),
 

crates/ruff_linter/src/rules/flake8_simplify/rules/split_static_string.rs

@@ -39,6 +39,8 @@ use crate::checkers::ast::Checker;
 /// ).split(",")
 /// ```
 ///
+/// as this is converted to `["a", "b"]` without any of the comments.
+///
 /// ## References
 /// - [Python documentation: `str.split`](https://docs.python.org/3/library/stdtypes.html#str.split)
 #[derive(ViolationMetadata)]