An artifact is not a publication. It needs a token to download, expires
after ninety days, and nothing outside GitHub can link to it, so a number
that only lives in an artifact is a number nobody can check.
A third job merges a green run's two payloads into
benchmarks/vs_vectorbt/results/latest.json and commits it. The two are
stored side by side rather than folded into one table: they run on two
runners, and timings from two machines are not rows of the same table.
Only a run where both measuring jobs came back green is published, and a
dispatch that pins an old version measures and reports without becoming
the published number.
