ci: migrate from GitLab CI to Gitea Actions

- Add Gitea Actions workflow (.gitea/workflows/ci.yaml)
- Update K8s deployment image registry to oci.unbound.se

.gitea/workflows/ci.yaml

@@ -16,9 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: buildtool/setup-buildtools-action@v1
       - name: Build and push
-        run: |
+        run: unset GITEA_TOKEN && build && push
-          unset GITHUB_REPOSITORY_OWNER GITEA_TOKEN
-          build && push
 
   deploy-prod:
     needs: build

build-tools-dockerfile

@@ -1,10 +0,0 @@
-FROM amd64/golang:1.25.5@sha256:ad03ba93327b8a6143b49373790b5d92c28067bdb814418509466122ee9c9e63 as builder
-WORKDIR /src
-COPY * ./
-RUN go get
-RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o geo-service .
-
-FROM scratch
-COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
-COPY --from=builder /src/geo-service /
-CMD ["/geo-service"]