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/http-kernel/HttpKernelInterface.php

@@ -40,9 +40,7 @@ interface HttpKernelInterface
      *                    (one of HttpKernelInterface::MAIN_REQUEST or HttpKernelInterface::SUB_REQUEST)
      * @param bool $catch Whether to catch exceptions or not
      *
-     * @return Response
-     *
      * @throws \Exception When an Exception occurs during processing
      */
-    public function handle(Request $request, int $type = self::MAIN_REQUEST, bool $catch = true);
+    public function handle(Request $request, int $type = self::MAIN_REQUEST, bool $catch = true): Response;
 }