minor #1315 Update PHP doc about annotations IsGranted (adpauly)

This PR was squashed before being merged into the main branch.

Discussion
----------

Update PHP doc about annotations IsGranted

The doc now suggests to use PHP attributes instead of "old" annotation for "IsGranted" instruction.
Sorry if my PR format doesn't match with your requirements. I just wanna help. :)

Commits
-------

81a39d8 Update PHP doc about annotations IsGranted

src/Controller/Admin/BlogController.php

@@ -112,7 +112,7 @@ public function new(Request $request, EntityManagerInterface $entityManager): Re
     public function show(Post $post): Response
     {
         // This security check can also be performed
-        // using an annotation: @IsGranted("show", subject="post", message="Posts can only be shown to their authors.")
+        // using a PHP attribute: #[IsGranted('show', subject: 'post', message: 'Posts can only be shown to their authors.')]
         $this->denyAccessUnlessGranted(PostVoter::SHOW, $post, 'Posts can only be shown to their authors.');
 
         return $this->render('admin/blog/show.html.twig', [