chore: add testruns for PHP 8.3 (#1222)

Co-authored-by: Christopher Georg <christopher.georg@sr-travel.de>
Co-authored-by: Jonathan Beliën <jbelien@users.noreply.github.com>

Author: 3 people

.github/workflows/provider.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['8.0', '8.1', '8.2']
+        php-version: ['8.0', '8.1', '8.2', '8.3']
     steps:
     - uses: actions/checkout@v4
     - name: Use PHP ${{ matrix.php-version }}