Fix benchmark comparison in bench_download.py tool

[Akirathan]

Pull Request Description

./bench_download.py tool stopped working after #12226. Because the artifacts on benchmark workflow runs were renamed. This PR just renames the artifacts (suggested in #12201 (comment)) and also adds some unit tests.

In many unit tests, I had to bump the date of the fetched data, because GH seems to delete workflow runs that are older than 2 years.

Note that yesterday, Benchmark Upload workflow started printing a warning that there is an unknown artifact name

Important Notes

Checklist

Please ensure that the following checklist has been satisfied before submitting the PR:

• The documentation has been updated, if necessary.
• Screenshots/screencasts have been attached, if there are any visual changes. For interactive or animated visual changes, a screencast is preferred.
• All code follows the
  Scala,
  Java,
  TypeScript,
  and
  Rust
  style guides. In case you are using a language not listed above, follow the Rust style guide.
• Unit tests have been written where possible.
• If meaningful changes were made to logic or tests affecting Enso Cloud integration in the libraries,
  or the Snowflake database integration, a run of the Extra Tests has been scheduled.
  • If applicable, it is suggested to paste a link to a successful run of the Extra Tests.

[Akirathan]

Manually scheduled https://github.com/enso-org/enso/actions/runs/13156491997/job/36714698889 finished successfully, and uploaded even the new artifacts as data. We are ready to merge.

GitHub

Benchmarks upload · enso-org/enso@428526c

Enso Analytics is a self-service data prep and analysis platform designed for data teams. - Benchmarks upload · 428526c