Add PHP 8.4 in tests matrix (#25)

Author: keradus

.github/workflows/ci.yaml

@@ -38,6 +38,7 @@ jobs:
           - php-version: '8.1'
           - php-version: '8.2'
           - php-version: '8.3'
+          - php-version: '8.4'
     steps:
       - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2