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/console/Descriptor/DescriptorInterface.php

@@ -20,5 +20,8 @@ use Symfony\Component\Console\Output\OutputInterface;
  */
 interface DescriptorInterface
 {
+    /**
+     * @return void
+     */
     public function describe(OutputInterface $output, object $object, array $options = []);
 }