update dashboard workflow (#211)

* update dashboard workflow

* run on workflow_dispatch

* trigger on PR to dev for debugging

* update build push action

* update context && file

* remove trigger on PR

* remove workflow_dispatch trigger; remove tag instruction

.github/workflows/update_dashboard.yml

@@ -33,13 +33,15 @@ jobs:
           uses: docker/metadata-action@v4
           with:
             images: ghcr.io/${{ github.repository }}/superset_df_dashboard
+            flavor: |
+              latest=auto
             tags: |
-              type=ref,event=branch
-              type=semver,event={{version}}
+              type=raw,value=latest,enable={{is_default_branch}}
 
         - name: Build and upload image
-          uses: docker/build-push-action@v4 
+          uses: docker/build-push-action@v4
           with:
+            context: dff/utils/docker
             file: dff/utils/docker/dockerfile_stats
             tags: ${{ steps.meta.outputs.tags }}
             labels: ${{ steps.meta.outputs.labels }}