Merge pull request #72 from oliverklee/task/update-gh-actions

[TASK] Upgrade the GitHub Actions

Author: sascha-egerer

.github/workflows/tests.yml

@@ -31,7 +31,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: "actions/checkout@v2"
+        uses: "actions/checkout@v3"
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@v2"