Added php 8.3 for test execution

Author: thirsch

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        php: ['7.4', '8.1', '8.2']
+        php: ['7.4', '8.1', '8.2', '8.3']
 
     name: PHP ${{ matrix.php }}