fix ci cache calculation

.github/workflows/build-server-image.yml

@@ -63,8 +63,8 @@ jobs:
       - name: Build and push
         uses: docker/build-push-action@v6
         with:
-          context: server-deploy
-          file: server-deploy/Dockerfile
+          context: .
+          file: Dockerfile
           # mc-server-runner is downloaded as linux_amd64 in the Dockerfile.
           platforms: linux/amd64
           push: true