(un)deprecate prefer_equal_for_default_values (dart-archive/linter#3898)

Author: pq

example/all.yaml

@@ -123,6 +123,7 @@ linter:
     - prefer_constructors_over_static_methods
     - prefer_contains
     - prefer_double_quotes
+    - prefer_equal_for_default_values
     - prefer_expression_function_bodies
     - prefer_final_fields
     - prefer_final_in_for_each

lib/src/rules/prefer_equal_for_default_values.dart

@@ -38,7 +38,8 @@ class PreferEqualForDefaultValues extends LintRule {
             name: 'prefer_equal_for_default_values',
             description: _desc,
             details: _details,
-            maturity: Maturity.deprecated,
+            // todo(pq): deprecate for 3.0 (https://github.com/dart-lang/linter/issues/3879)
+            maturity: Maturity.stable,
             group: Group.style);
 
   @override