Show test failures of ci-meson as annotations

[user202729]

Follow-up to #36938 and #37738 , this PR shows the test failures of ci-meson.yml workflow as GitHub annotations, which has the advantage that you don't need to scroll through the whole log to view the failed tests.

(actually I just search for Failed examples, but this is not foolproof)

Previously only build.yml got this feature.

There's a disadvantage, then the file and line numbers are no longer shown in the downloaded log file, instead only [error] is shown (but this is trivially fixable by printing the format in both old and new ways when --format github is passed). I think if everyone views the annotations instead of reading the raw log anyway, it shouldn't matter too much.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes. (no functionality change)
• I have updated the documentation and checked the documentation preview. (no documentation change)

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit 763521d; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[user202729]

Looks like it's working. (before the change, the highlighted part would always be test-long or test-new instead.)

[saraedum]

Looks good to me. But maybe @tobiasdiez (or somebody else) could sign off on this one?