infra: [FIXME] add docker build ci

This currently doesn't work. I gotta figure out how to add a ci bot
properly to gitea

.gitea/workflows/docker.yml

@@ -0,0 +1,41 @@
+# name: Build gentoo-utils docker image
+
+# on:
+#   push:
+#     branches:
+#       - master
+#     paths:
+#       - '.docker/Dockerfile'
+#   pull_request:
+#     paths:
+#       - '.docker/Dockerfile'
+#   workflow_dispatch:
+
+# jobs:
+#   build-docker:
+#     runs-on: ubuntu-latest
+
+#     steps:
+#       - name: Checkout repo
+#         uses: actions/checkout@v4
+
+#       - name: Set up Docker buildx
+#         uses: docker/setup-buildx-action@v3
+
+#       - name: Log in to Github Container Registry
+#         uses: docker/login-action@v3
+#         with:
+#           registry: ${{ secrets.PIPELINE_REGISTRY_URL }}
+#           username: ${{ github.actor }}
+#           password: ${{ secrets.GITHUB_TOKEN }}
+
+#       - name: Extract metadata for Docker
+#         id: meta
+#         uses: docker/metadata-action@v5
+#         with:
+#           images: ghcr.op/${{ github.repository_owner }}/gentoo-utils-builder
+#           tags: |
+#             type=raw,value=latest
+#             type=sha,prefix={{branch}}-
+
+#       -name: Build and push docker image