Add PHP 8.4 to system tests matrix

Author: eclipxe13

.github/workflows/system.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: "ubuntu-latest"
     strategy:
       matrix:
-        php-version: ['8.2', '8.3']
+        php-version: ['8.2', '8.3', '8.4']
     steps:
       - name: Checkout
         uses: actions/checkout@v4