fixed dockerfile error

Author: NiklasAbraham

.github/workflows/release_image.yaml

@@ -28,7 +28,7 @@ jobs:
         uses: docker/build-push-action@3b5e8027fcad23fda98b2e3ac259d8d67585f671
         with:
           context: .
-          file: ./Dockerfile
+          file: ./jupyterlab/Dockerfile
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}