[AutoImport] Optimize ClassRenamingPostRector with stop on enterNode()

[samsonasik]

similar with PR:

• Optimise post rectors #6240

the process already done on beforeTraverse()

We stop the traversal because all the work has already been done in the beforeTraverse() function

Using STOP_TRAVERSAL is usually dangerous as it will stop the processing of all your nodes for all visitors
but since the PostFileProcessor is using direct new NodeTraverser() and traverse() for only a single
visitor per execution, using stop traversal here is safe,

ref

rector-src/src/PostRector/Application/PostFileProcessor.php

Lines 59 to 61 in fc1e742

	$nodeTraverser = new NodeTraverser();
	$nodeTraverser->addVisitor($postRector);
	$stmts = $nodeTraverser->traverse($stmts);

[samsonasik]

PHPStan notice seems due to new PHPStan release

https://github.com/phpstan/phpstan/releases/tag/2.1.26

I will fix phpstan notice in separate PR.

• Bump PHPStan 2.1.26 and fixes phpstan notice #7296

[samsonasik]

All checks have passed 🎉 @TomasVotruba I am merging it ;)