workflows: add workflow to push cleanup image

.github/workflows/cleanup.yml

@@ -0,0 +1,40 @@
+name: push cleanup-bm image
+
+on:
+  pull_request:
+    paths:
+      - .github/workflows/cleaup.yml
+      - packages/**
+
+env:
+  container_registry: ghcr.io/edgelesssys
+
+jobs:
+  push:
+    name: "push cleanup image"
+    runs-on: ubuntu-22.04
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871 # v4.2.1
+      - if: ${{ !inputs.self-hosted }}
+        uses: ./.github/actions/setup_nix
+        with:
+          githubToken: ${{ secrets.GITHUB_TOKEN }}
+          cachixToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+      - name: Log in to ghcr.io Container registry
+        uses: docker/login-action@9780b0c442fbb1117ed29e0efdff1e18412f7567 # v3.3.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - uses: nicknovitski/nix-develop@a2060d116a50b36dfab02280af558e73ab52427d # v1.1.0
+      - name: Create justfile.env
+        run: |
+          cat <<EOF > justfile.env
+          container_registry=${{ env.container_registry }}
+          EOF
+      - name: Build and push just push cleanup-bm image
+        run: |
+          just push cleanup-bm