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/error-handler/ErrorRenderer/CliErrorRenderer.php

@@ -23,9 +23,6 @@ class_exists(CliDumper::class);
  */
 class CliErrorRenderer implements ErrorRendererInterface
 {
-    /**
-     * {@inheritdoc}
-     */
     public function render(\Throwable $exception): FlattenException
     {
         $cloner = new VarCloner();