ci: update actions/checkout version

Author: JanTvrdik

.github/workflows/qa.yaml

@@ -50,7 +50,7 @@ jobs:
           --health-retries 10
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}