Merge pull request #7 from PartTimeLegend/renovate/actions-checkout-4.x

Update actions/checkout action to v4

.github/workflows/docker.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2  # Check out your repository's code
+        uses: actions/checkout@v4  # Check out your repository's code
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3