try workflow with local runner

.gitea/workflows/bluebuild.yml

@@ -0,0 +1,22 @@
+name: bluebuild
+on:
+  schedule:
+    - cron: "00 00 * * *"
+  push:
+    paths-ignore:
+      - "**.md"
+  workflow_dispatch:
+
+jobs:
+  bluebuild:
+    name: Build Custom Image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Build Custom Image
+        uses: blue-build/github-action@v1.11
+        with:
+          recipe: ${{ matrix.recipe }}
+          cosign_private_key: ${{ secrets.SIGNING_SECRET }}
+          registry_token: ${{ github.token }}
+          # Some Gitea versions prefer:
+          # registry_token: ${{ secrets.GITHUB_TOKEN }}