feat: PHP 8.4 compatibility (#1665)

* PHP 8.4 compatibility

* Added PHP versions to the pr-validation.yml

Author: hubipe

.github/workflows/pr-validation.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: ['7.4', '8.0', '8.1', '8.2']
+        php-versions: ['7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
     steps:
     - name: Setup PHP
       uses: shivammathur/setup-php@v2

src/GraphRequestAdapter.php

@@ -29,7 +29,7 @@ class GraphRequestAdapter extends BaseGraphRequestAdapter
      * @param AuthenticationProvider $authenticationProvider
      * @param Client|null $httpClient
      */
-    public function __construct(AuthenticationProvider $authenticationProvider, Client $httpClient = null)
+    public function __construct(AuthenticationProvider $authenticationProvider, ?Client $httpClient = null)
     {
         parent::__construct($this->getTelemetryConfig(), $authenticationProvider, null, null, $httpClient);
     }