Add a nightly docker tag built whenever there's a push to main

.github/workflows/release.yml

@@ -3,6 +3,10 @@ name: Release Pipeline
 on:
   release:
     types: [created]
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
 
 env:
   IMAGE_NAME: wygiwyh
@@ -29,7 +33,21 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Build and push image
+      - name: Build and push nightly image
+        if: github.event_name == 'push' || github.event_name == 'pull_request'
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./docker/prod/django/Dockerfile
+          push: true
+          provenance: false
+          tags: ${{ secrets.DOCKERHUB_USERNAME }}/${{ env.IMAGE_NAME }}:nightly
+          platforms: linux/amd64,linux/arm64
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Build and push release image
+        if: github.event_name == 'release'
         uses: docker/build-push-action@v6
         with:
           context: .