N°6934 - Symfony 6.4 - upgrade Symfony bundles to 6.4 (#580)

* Update Symfony lib to version ~6.4.0
* Update code missing return type
* Add an iTop general configuration entry to store application secret (Symfony mandatory parameter)
* Use dependency injection in ExceptionListener & UserProvider classes

lib/symfony/routing/RequestContextAwareInterface.php

@@ -15,13 +15,13 @@ interface RequestContextAwareInterface
 {
     /**
      * Sets the request context.
+     *
+     * @return void
      */
     public function setContext(RequestContext $context);
 
     /**
      * Gets the request context.
-     *
-     * @return RequestContext
      */
-    public function getContext();
+    public function getContext(): RequestContext;
 }