Test against PHP 8.3

Author: snapshotpl

.github/workflows/run-tests.yml

@@ -9,7 +9,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ ubuntu-latest ]
-        php: [ 5.6, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, 8.1, 8.2 ]
+        php: [ 5.6, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, 8.1, 8.2, 8.3 ]
         dependency-version: [ prefer-stable ]
 
     name: P${{ matrix.php }} - ${{ matrix.dependency-version }} - ${{ matrix.os }}