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/config/Loader/DirectoryAwareLoaderInterface.php

@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Loader;
+
+/**
+ * A loader that can be scoped to a given filesystem directory.
+ *
+ * @author Alexander M. Turek <me@derrabus.de>
+ */
+interface DirectoryAwareLoaderInterface
+{
+    public function forDirectory(string $currentDirectory): static;
+}