Change error identifier to method.purity

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

src/Rules/Methods/MethodSignatureRule.php

@@ -73,7 +73,7 @@ public function processNode(Node $node, Scope $scope): array
 					$method->getName(),
 					$parentMethodDeclaringClass->getDisplayName(),
 					$parentMethod->getName(),
-				))->identifier('method.impureOverridePure')->build();
+				))->identifier('method.purity')->build();
 			}
 
 			$parentVariants = $parentMethod->getVariants();