[release-2.0] Set docker image name properly when releasing (#2873)

This is an automated cherry-pick of #2872

/assign JohnNiang

```release-note
None
```

.github/workflows/halo.yaml

@@ -56,7 +56,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: halo-sigs/actions/halo-next-docker-build@main # change the version to specific ref or release tag while the action is stable.
         with:
-          image-name: halo-dev
+          image-name: ${{ github.event_name == 'release' && 'halo' || 'halo-dev' }}
           ghcr-token: ${{ secrets.GHCR_TOKEN }}
           dockerhub-user: ${{ secrets.DOCKER_USERNAME }}
           dockerhub-token: ${{ secrets.DOCKER_TOKEN }}