Wrap the pr_labels entrypoint in main(argv=None) with UTF-8 stream
reconfiguration using backslashreplace error handling.
Catch CalledProcessError when querying repository or pull request details
and report cleanly via parser.error rather than propagating an unhandled
traceback.
title_ids took every title ID from the Unblocks field, so a field that
starts with "none" and then names a title for context ("none by
itself; foundation for PPSA27836 in #6570") got the unblocks title
label. A field that starts with "none" now names no title.
Co-Authored-By: Claude Opus 5.5 <[email protected]>