Fix the GH workflow to push the docker image

.github/workflows/docker-image.yml

@@ -4,19 +4,23 @@ on:
   push:
     tags:
       - 'v*'  # This will match any tag that starts with 'v'
-
+  pull_request:  # Add this to run on PRs
+    branches:
+      - main     # Assuming your default branch is 'main'
 jobs:
   build:
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
+      with:
+        submodules: recursive
     - uses: docker/setup-qemu-action@v3
     - uses: docker/setup-buildx-action@v3
     - uses: docker/build-push-action@v5
       with:
         context: .
-        tags: ghcr.io/hasura/ndc-calcite:${{ github.ref_name }}  # Use the tag name for the Docker image
+        tags: ghcr.io/hasura/ndc-calcite:${{ github.event_name == 'pull_request' && format('pr-{0}', github.event.number) || github.ref_name }}
         platforms: linux/amd64,linux/arm64
         cache-from: type=gha
         cache-to: type=gha,mode=max