ci: remove php 8.0 and add php 8.4 to the test runner

Author: thelfensdrfer

.github/workflows/tests.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php-versions: ['8.0', '8.1', '8.2']
+        php-versions: ['8.1', '8.2', '8.3', '8.4']
 
     name: PHPUnit ${{ matrix.php-versions }}
     steps: