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/dependency-injection/Extension/ExtensionInterface.php

@@ -23,6 +23,10 @@ interface ExtensionInterface
     /**
      * Loads a specific configuration.
      *
+     * @param array<array<mixed>> $configs
+     *
+     * @return void
+     *
      * @throws \InvalidArgumentException When provided tag is not defined in this extension
      */
     public function load(array $configs, ContainerBuilder $container);