ci: test 8.4

Author: jiripudil

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-version: ['8.1', '8.2', '8.3']
+        php-version: ['8.1', '8.2', '8.3', '8.4']
     steps:
       - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2