The lock was written against the rolling tags because the per-version
releases did not exist when it was generated, and the refresh tool assumed
PostgreSQL was tagged by major, which it is not: the release that never
changes is postgresql-18.6, whilst only the rolling one says 18. The tool
now resolves a major to the version pgbuild's manifest names, and a tag that
does not exist is an error rather than something to fall back from, since a
lock recording an archive nobody can fetch is worse than no lock at all.
84a76baa8e