Streamline scheduled workflow with default one

.github/workflows/scheduled_builds.yml

@@ -13,11 +13,15 @@ jobs:
         with:
           ref: stable
           submodules: recursive
-      - name: Prepare
+      - name: Prepare tags
         id: prep
-        run: |
-          TAGS=${{ secrets.DOCKER_REPOSITORY }}:stable
-          echo ::set-output name=tags::${TAGS}
+        uses: crazy-max/ghaction-docker-meta@v1
+        with:
+          images: |
+            ${{ secrets.DOCKER_REPOSITORY }}
+            ${{ secrets.GHCR_REPOSITORY }}
+          tag-custom: stable
+          tag-custom-only: true
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
       - name: Set up Docker Buildx
@@ -28,6 +32,12 @@ jobs:
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ secrets.GHCR_USERNAME }}
+          password: ${{ secrets.GHCR_PASSWORD }}
       - name: Build image locally
         uses: docker/build-push-action@v2
         with: