Update tagging of the docker image on release, push to master & PR

- Tag docker image with `tag_name' on release (i.e tag push)
- Else tag with 'pre' on push to master
- Else tag with 'dev' on push to PR branch

- Only tag the latest release with release tag
  Previously the latest commit on master was being tagged with the
  latest tag. This doesn't sync with the release cadence of the rest
  of Khoj

.github/workflows/dockerize.yml

@@ -16,7 +16,8 @@ on:
   workflow_dispatch:
 
 env:
-  DOCKER_IMAGE_TAG: ${{ github.ref == 'refs/heads/master' && 'latest' || github.ref_name }}
+  # Tag Image with tag name on release, else with 'pre' if push to master
+  DOCKER_IMAGE_TAG: ${{ github.ref_type == 'tag' && github.ref_name || 'pre' }}
 
 jobs:
   build:
@@ -47,7 +48,9 @@ jobs:
           file: Dockerfile
           platforms: linux/amd64, linux/arm64
           push: true
-          tags: ghcr.io/${{ github.repository }}:${{ env.DOCKER_IMAGE_TAG }}
+          tags: |
+            ghcr.io/${{ github.repository }}:${{ env.DOCKER_IMAGE_TAG }}
+            ${{ github.ref_type == 'tag' && 'ghcr.io/${{ github.repository }}-cloud:latest' || '' }}
           build-args: |
             VERSION=${{ steps.hatch.outputs.version }}
             PORT=42110