Unnecessary reset of requirements updates

[Kevin L. Mitchell]

When a change is merged to global-requirements.txt, a review is proposed to all impacted repositories…unless such a review is already pending. Merging a change to global-requirements.txt *also* updates all such pending reviews, *even if the project in question would not be impacted*. This can lead to a lot of unnecessary resets; I've seen some of these reviews get approved, then "updated" before the merge can complete, several times in a row.