For example: https://github.com/flutter/flutter/pull/101834 Tree has been green since yesterday, but the `luci-flutter` status is still red. <img width="1033" alt="Screen Shot 2022-06-29 at 9 50 26 AM" src="https://user-images.githubusercontent.com/54558023/176492299-31e8c11c-8b71-43bd-a0a1-0427d57d301b.png"> Culprit: [pull list api ](https://docs.github.com/en/rest/pulls/pulls#list-pull-requests)returns 30 PRs by default. We should extend the number to cover relatively old PRs.