Post test failures summary to a PR comment as well as to CI

[neilmayhew]

Description

We already have a summary test failures being posted to the CI summary view. This posts a copy to a PR comment as well (if the CI is for a PR).

Checklist

• Commits in meaningful sequence and with useful messages.
• Tests added or updated when needed.
• CHANGELOG.md files updated for packages with externally visible changes.
  NOTE: New section is never added with the code changes. (See RELEASING.md).
• Versions updated in .cabal and CHANGELOG.md files when necessary, according to the
  versioning process.
• Version bounds in .cabal files updated when necessary.
  NOTE: If bounds change in a cabal file, that package itself must have a version increase. (See RELEASING.md).
• Code formatted (use scripts/fourmolize.sh).
• Cabal files formatted (use scripts/cabal-format.sh).
• CDDL files are up to date (use scripts/gen-cddl.sh)
• hie.yaml updated (use scripts/gen-hie.sh).
• Self-reviewed the diff.

[lehins]

Please make sure that it will not post any comments for draft PRs

[f-f]

What is the marker for?

[neilmayhew]

What is the marker for?

It's to enable a previous comment to be located and updated rather than adding a new comment. This cuts down the noise. The marker is placed in an HTML comment, so it doesn't show up in the rendered markdown.

This was Claude's idea, and I think it's a good one. It originally called the action "Upsert PR Comment" but "upsert" is such an ugly word I chose to remove it 😄

[neilmayhew]

Please make sure that it will not post any comments for draft PRs

Thanks for the reminder. I think you mentioned this when we first talked about it.

I've pushed a commit that addresses this.

[f-f]

👏

[github-actions]

Test Failures