[TASK] Add PHP 8.3 to CI matrix

Author: lolli42

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
+        php: ['7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
 
     steps:
       - uses: actions/checkout@v4