minor #17452 Fix confusing example of type-hinting the Request object (theofidry)

This PR was merged into the 4.4 branch.

Discussion
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Fix confusing example of type-hinting the Request object

As far as I can see, this piece of doc is incorrect as `$firstName` and `$lastName` wouldn't be injected properly there and the piece of doc in question is not about those two parameters either.

As such I propose to remove them from the example to prevent any confusion.

Commits
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4351c89 Fix bad copy/paste

Author: javiereguiluz

controller.rst

@@ -381,7 +381,7 @@ object. To access it in your controller, add it as an argument and
     use Symfony\Component\HttpFoundation\Response;
     // ...
 
-    public function index(Request $request, string $firstName, string $lastName): Response
+    public function index(Request $request): Response
     {
         $page = $request->query->get('page', 1);