feat(pr): expandCodeOwnersGroups (#25317)

docs/usage/configuration-options.md

lib/config/options/index.ts

lib/config/types.ts

lib/modules/platform/gitlab/http.ts

lib/modules/platform/gitlab/index.spec.ts

lib/modules/platform/gitlab/index.ts

lib/modules/platform/types.ts

lib/util/common.ts

lib/workers/repository/init/index.spec.ts

lib/workers/repository/init/index.ts

lib/workers/repository/update/pr/participants.spec.ts

lib/workers/repository/update/pr/participants.ts