Update latest image periodically.

.github/workflows/dockerimage.yml

@@ -9,6 +9,8 @@ on:
       - .github/workflows/dockerimage.yml
       - Dockerfile
       - pyproject.toml
+  schedule:
+    - cron: '0 23 * * SUN'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref == 'refs/heads/main' && github.run_number || github.ref }}
@@ -37,7 +39,7 @@ jobs:
         echo "TAG_NAME=${TAG_NAME}" >> $GITHUB_ENV
 
     - name: Login to Docker Hub
-      if: ${{ github.event_name == 'release' }}
+      if: ${{ github.event_name == 'release' || github.event_name == 'schedule' }}
       uses: docker/login-action@v3
       with:
         username: optunabot
@@ -49,12 +51,31 @@ jobs:
     - name: Set up Docker Buildx
       uses: docker/setup-buildx-action@v3
 
-    - name: Build and push
+    - name: Build and push (Release)
+      if: ${{ github.event_name == 'release' }}
       uses: docker/build-push-action@v6
       with:
         context: .
         platforms: linux/amd64,linux/arm64
-        push: ${{ github.event_name == 'release' }}
+        push: true
         tags: |
           ${{ env.DOCKER_HUB_BASE_NAME }}:${{ env.TAG_NAME }}
           ${{ env.DOCKER_HUB_BASE_NAME }}:latest
+
+    - name: Build and push (Schedule)
+      if: ${{ github.event_name == 'schedule' }}
+      uses: docker/build-push-action@v6
+      with:
+        context: .
+        platforms: linux/amd64,linux/arm64
+        push: true
+        tags: |
+          ${{ env.DOCKER_HUB_BASE_NAME }}:latest
+
+    - name: Build only (Pull Request)
+      if: ${{ github.event_name == 'pull_request' }}
+      uses: docker/build-push-action@v6
+      with:
+        context: .
+        platforms: linux/amd64,linux/arm64
+        push: false