[Chapel Merge] Set cancel-in-progress for old PR checks against same SHA

Branch: refs/heads/main
Revision: 33828cca63db63dd3e708c20f0dca916e862bc45
Author: arifthpe
Link: Set cancel-in-progress for old PR checks against same SHA by arifthpe · Pull Request #29290 · chapel-lang/chapel · GitHub
Log Message:
Set cancel-in-progress for old PR checks against same SHA (#29290)

Cancel previous PR check runs against the same SHA.

This fixes an unintended consequence of
Cancel superseded or destroyed merge group workflow runs by arifthpe · Pull Request #29274 · chapel-lang/chapel · GitHub, in which when labeling
or unlabeling a PR, a new check run is queued up and has to wait for the
previous one to complete. This would also happen for closing and
reopening a PR. In all of these cases, I think we don't want to have to
wait around for the latest run to start, and also don't care to see the
previous run's results.

Follow up to Cancel superseded or destroyed merge group workflow runs by arifthpe · Pull Request #29274 · chapel-lang/chapel · GitHub.

[reviewed by @jabraham17 , thanks!]

Compare: Comparing 379a25dc619cbad7761b62afb25ee44a3599e50f...6ff10e8150beabcfaea85bb783c95eab5b71bfaa · chapel-lang/chapel · GitHub

Diff:
M .github/workflows/trigger-pr-checks.yml
https://github.com/chapel-lang/chapel/pull/29290.diff