Deprecate PT004 and PT005 (#12837)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

crates/ruff_linter/src/codes.rs

@@ -790,8 +790,8 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Flake8PytestStyle, "001") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestFixtureIncorrectParenthesesStyle),
         (Flake8PytestStyle, "002") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestFixturePositionalArgs),
         (Flake8PytestStyle, "003") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestExtraneousScopeFunction),
-        (Flake8PytestStyle, "004") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestMissingFixtureNameUnderscore),
-        (Flake8PytestStyle, "005") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestIncorrectFixtureNameUnderscore),
+        (Flake8PytestStyle, "004") => (RuleGroup::Deprecated, rules::flake8_pytest_style::rules::PytestMissingFixtureNameUnderscore),
+        (Flake8PytestStyle, "005") => (RuleGroup::Deprecated, rules::flake8_pytest_style::rules::PytestIncorrectFixtureNameUnderscore),
         (Flake8PytestStyle, "006") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestParametrizeNamesWrongType),
         (Flake8PytestStyle, "007") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestParametrizeValuesWrongType),
         (Flake8PytestStyle, "008") => (RuleGroup::Stable, rules::flake8_pytest_style::rules::PytestPatchWithLambda),

crates/ruff_linter/src/rules/flake8_pytest_style/rules/fixture.rs

@@ -170,6 +170,10 @@ impl AlwaysFixableViolation for PytestExtraneousScopeFunction {
     }
 }
 
+/// ## Deprecation
+/// Marking fixtures that do not return a value with an underscore
+/// isn't a practice recommended by the pytest community.
+///
 /// ## What it does
 /// Checks for `pytest` fixtures that do not return a value, but are not named
 /// with a leading underscore.
@@ -227,6 +231,10 @@ impl Violation for PytestMissingFixtureNameUnderscore {
     }
 }
 
+/// ## Deprecation
+/// Marking fixtures that do not return a value with an underscore
+/// isn't a practice recommended by the pytest community.
+///
 /// ## What it does
 /// Checks for `pytest` fixtures that return a value, but are named with a
 /// leading underscore.