Update docker workflow

Author: ubaumann

.github/workflows/docker-image.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Login to Docker Hub
       uses: docker/login-action@v1