Update ci.yml

Author: robiningelbrecht

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: [ '8.1', '8.2' ]
+        php-versions: [ '8.1', '8.2', '8.3', '8.4' ]
 
     steps:
       # https://github.com/marketplace/actions/setup-php-action