Gate gather-refs on trigger-system-tests label in PR workflow

[PranjalManhgaye]

Fix #682 (part 1)

The System tests (PR) workflow runs on any pull_request: labeled event. Previously, gather-refs ran for every label add (making 7 GitHub API calls), while run-system-tests only ran when the label was trigger-system-tests. This wasted API quota for labels like "bug" or "GSoC".

This PR gates the gather-refs job on the same condition as run-system-tests:
if: github.event.label.name == 'trigger-system-tests'

The workflow now skips entirely for non-trigger labels, reducing GitHub API usage.

Per maintainer feedback in #723, authentication (token/App ID) is deferred and can be added separately if rate limits persist.

Checklist:

• I added a summary of any user-facing changes (compared to the last release) in changelog-entries/682.md.
• I will remember to squash-and-merge, providing a useful summary of the changes when merging.

[kishansinghifs1]

Can closed this as duplicate of #723.

[PranjalManhgaye]

thanks for the comment. I opened #733 as the minimal part 1 fix for #682 after the discussion in #723 (just gating gather-refs on the trigger-system-tests label, without auth changes). From my side I’m happy for maintainers to merge whichever PR they prefer and close the other as duplicate

[precice-bot]

This pull request has been mentioned on preCICE Forum on Discourse. There might be relevant details there:

https://precice.discourse.group/t/gsoc-2026-pranjal-manhgaye/2769/6

[MakisH]

Thank you both for addressing this. I will indeed close this one as duplicate of #723.

In general, whenever there is a PR under review, a better use of resources is to help refine the respective PR, than start a new one, unless the first is abandoned (for which I would expect at least several weeks of inactivity, in most cases).