feat(ci): add nightly cron rebuild workflow

.gitea/workflows/cron.yaml

@@ -0,0 +1,45 @@
+name: Nightly Rebuild
+
+on:
+  schedule:
+    - cron: '0 0 * * *'
+
+jobs:
+  hadolint:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd314b611f4172ccec0e10 # v6
+      - uses: hadolint/hadolint-action@2332a7b74a6de0dda2e2221d575162eba76ba5e5 # v3.3.0
+        with:
+          dockerfile: Dockerfile
+
+  build-push:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd314b611f4172ccec0e10 # v6
+        with:
+          fetch-depth: 0
+      - uses: docker/setup-buildx-action@d7f5e7f509e45cec5ec5cec634d7e93b0d3df5 # v4
+      - uses: docker/login-action@650006c6eb7dba73a9959e03b0d7f5ca915beee # v4
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - id: get-latest-tag
+        run: |
+          TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
+          echo "tag=$TAG" >> $GITHUB_OUTPUT
+      - id: meta
+        uses: docker/metadata-action@80c7e94dd9b9319bd5e6e1924ec29b2a2a2e9 # v6
+        with:
+          images: jcabillot/calibre
+          tags: |
+            type=raw,value=latest
+            type=raw,value=${{ steps.get-latest-tag.outputs.tag }},enable=${{ steps.get-latest-tag.outputs.tag != '' }}
+      - uses: docker/build-push-action@f9f3042f27e2859062d64b8f5b70fefb5195baf # v7.2.0
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          pull: true