Test against php 8.3

Author: nickdnk

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php: [ '7.3', '7.4', '8.0', '8.1', '8.2' ]
+        php: [ '7.3', '7.4', '8.0', '8.1', '8.2', '8.3' ]
     steps:
       - uses: actions/checkout@v2
       - run: mkdir -p build/logs