[Improvement][CI] CI of unmerged PRs should rerun if a new PR gets merged

[EricGao888]

Search before asking

• I had searched in the issues and found no similar feature requirement.

Description

Suppose we have two PR A and B. A or B could pass CI but A and B together cause bugs and fail CI.

If the CI of A and B both had passed on 8 a.m. and A got merged on 9 a.m., in current settings, CI of B still looked good and could be merged. As a result, A and B together cause new bugs and PRs after them will fail the CI.

Therefore, we need to force the CI of unmerged PRs to rerun once a new PR gets merged.

Personally I have seen this kind of bugs happen in DS repo several times.

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[EricGao888]

BTW, this issue may happen during we release a new version, which is highly risky.

[zhongjiajie]

We can do that by turn on update to date for each PR ref https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/keeping-your-pull-request-in-sync-with-the-base-branch but it will take our maintainer much time and ci workflow more crowded