added workflow to build v7 demoshop image

.github/workflows/build-v7-image.yml

@@ -0,0 +1,88 @@
+name: Build image for v7 Demoshop
+
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+
+on:
+  schedule:
+    - cron: '16 6 * * *'
+  push:
+    branches:
+      - b-7.0.x
+  repository_dispatch:
+    types: [docker-build]
+
+env:
+  # Use docker.io for Docker Hub if empty
+  REGISTRY: ghcr.io
+  # github.repository as <account>/<repo>
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+            ref: b-7.0.x
+
+      - name: Checkout dockerfiles
+        uses: actions/checkout@v3
+        with:
+          repository: OXID-eSales/module-demoshop-images
+          token: ${{ secrets.GH_PAT }} # `GH_PAT` is a secret that contains your PAT
+          path: dockerfiles
+
+      - name: move dockerfiles to root folder
+        run: mv dockerfiles/unzer/* .
+
+      - name: downcase REPO
+        run: |
+          echo "REPO=${GITHUB_REPOSITORY,,}" >>${GITHUB_ENV}
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      # Login against a Docker registry except on PR
+      # https://github.com/docker/login-action
+      - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v2
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # Extract metadata (tags, labels) for Docker
+      # https://github.com/docker/metadata-action
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@818d4b7b91585d195f67373fd9cb0332e31a7175
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      # Build and push Docker image with Buildx (don't push on PR)
+      # https://github.com/docker/build-push-action
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          file: ./Dockerfile.v7
+          platforms: linux/amd64,linux/arm64
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: |
+            ${{ env.REGISTRY }}/${{ env.REPO }}:v7
+          secrets: |
+            "github_token=${{ secrets.GITHUB_TOKEN }}"
+