refactor(workers): Prefer interface over type (#16727)

lib/workers/repository/init/types.ts

lib/workers/repository/process/extract-update.ts

...repository/update/branch/execute-post-upgrade-commands.ts

lib/workers/repository/update/branch/status-checks.ts

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

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