refactor: update build docker action

Author: xuwei-fit2cloud

.github/workflows/build_docker.yml

@@ -48,7 +48,7 @@ jobs:
     - name: Build and push Docker image
       uses: docker/build-push-action@v4
       with:
-        context: ./backend
+        context: .
         push: true
         tags: |
           ${{ secrets.DOCKERHUB_REGISTRY }}/dataease-v2/sqlbot:latest