Added PHP 8.3 to CI.

Author: corpsee

.github/workflows/ci.yaml

@@ -8,7 +8,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                php-version: ['8.1', '8.2']
+                php-version: ['8.1', '8.2', '8.3']
 
         steps:
             - uses: actions/checkout@v2