CI for building releases Closes https://github.com/bazelbuild/rules_docker/issues/1794 Inspired by https://github.com/buchgr/bazel-remote/blob/master/.github/workflows/release.yml https://sourcegraph.com/github.com/bazelbuild/rules_docker/-/blob/container/go/cloudbuild.yaml#L133 https://ncorti.com/blog/howto-github-actions-build-matrix