Add hash as part of key for docker cache

as https://github.com/satackey/action-docker-layer-caching#inputs notes.

.github/workflows/docker.yml

@@ -19,7 +19,7 @@ jobs:
       continue-on-error: true
       with:
         path: ~/.cache/images
-        key: ${{ matrix.images }}-cache-images
+        key: ${{ matrix.images }}-cache-images-{hash}
 
     - name: Docker Build ${{ matrix.images }}
       run: docker-compose pull ${{ matrix.images }}