[internal] Mark beforeTraverse() in AbstractRector as @Final to prevent override and miss-use (#7727)

Author: TomasVotruba

phpstan.neon

@@ -408,3 +408,8 @@ parameters:
         -
             identifier: rector.noOnlyNullReturnInRefactor
             path: rules/TypeDeclaration/Rector/StmtsAwareInterface/DeclareStrictTypesRector.php
+
+        # handle next with FileNode
+        -
+            identifier: method.parentMethodFinalByPhpDoc
+            path: rules/TypeDeclaration/Rector/StmtsAwareInterface/DeclareStrictTypesRector.php

src/Rector/AbstractRector.php

@@ -106,6 +106,10 @@ public function autowire(
     }
 
     /**
+     * @final Avoid override to prevent unintended side-effects. Use enterNode() or @see \Rector\Contract\PhpParser\DecoratingNodeVisitorInterface instead.
+     *
+     * @internal
+     *
      * @return Node[]|null
      */
     public function beforeTraverse(array $nodes): ?array