Merge branch '5.4' into 6.0

* 5.4:
  Method getCharset with proper returning type
  Fix: Linebreak
  Inappropriate usage of Parameter Conversion
  [Lock] Add classes's link

Author: javiereguiluz

components/lock.rst

@@ -72,7 +72,8 @@ method can be safely called repeatedly, even if the lock is already acquired.
 Serializing Locks
 ------------------
 
-The ``Key`` contains the state of the ``Lock`` and can be serialized. This
+The :class:`Symfony\\Component\\Lock\\Key` contains the state of the
+:class:`Symfony\\Component\\Lock\\Lock` and can be serialized. This
 allows the user to begin a long job in a process by acquiring the lock, and
 continue the job in another process using the same lock::
 

reference/configuration/kernel.rst

@@ -39,7 +39,7 @@ charset::
 
     class Kernel extends BaseKernel
     {
-        public function getCharset()
+        public function getCharset(): string
         {
             return 'ISO-8859-1';
         }

routing.rst

@@ -1305,7 +1305,7 @@ when importing the routes.
             }
 
             #[Route('/{_locale}/posts/{slug}', name: 'show')]
-            public function show(Post $post): Response
+            public function show(string $slug): Response
             {
                 // ...
             }