Push Docker images to the master tag. (#2579)

.github/workflows/docker.yaml

@@ -18,9 +18,10 @@ name: Release to Docker
 on:
   workflow_dispatch:
   push:
-    # only publish on version tags
+    branches:
+      - master # publish to 'master' tag
     tags:
-      - 'v*.*.*'
+      - 'v*.*.*' # publish on version tags, updates 'latest' tag
 jobs:
   docker:
     runs-on: ubuntu-latest
@@ -35,6 +36,7 @@ jobs:
             livekit/livekit-server
           # generate Docker tags based on the following events/attributes
           tags: |
+            type=ref,event=branch
             type=semver,pattern=v{{version}}
             type=semver,pattern=v{{major}}.{{minor}}
 
@@ -56,6 +58,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
@@ -66,7 +69,7 @@ jobs:
         uses: docker/build-push-action@v5
         with:
           context: .
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
           platforms: linux/amd64,linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}