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/css-selector/Node/SelectorNode.php

@@ -23,8 +23,8 @@ namespace Symfony\Component\CssSelector\Node;
  */
 class SelectorNode extends AbstractNode
 {
-    private $tree;
-    private $pseudoElement;
+    private NodeInterface $tree;
+    private ?string $pseudoElement;
 
     public function __construct(NodeInterface $tree, string $pseudoElement = null)
     {
@@ -42,9 +42,6 @@ class SelectorNode extends AbstractNode
         return $this->pseudoElement;
     }
 
-    /**
-     * {@inheritdoc}
-     */
     public function getSpecificity(): Specificity
     {
         return $this->tree->getSpecificity()->plus(new Specificity(0, 0, $this->pseudoElement ? 1 : 0));