The GPG/OpenPGP secrets engine needs a Gitea repo to hold its source and run
its Woodpecker PR/release pipelines.
- Add config/git.unkin.net/unkin/repository/vault-plugin-secrets-gpg.yaml
(public, main default branch, squash-only, main branch protection gated on
the pre-commit/build/test PR checks), mirroring the sibling
vault-plugin-secrets-bind-tsig repo.