Inconsistent defaults: successful builds can be manually retried, but not individual steps

[huonw]

With #328/retry.manual.permit_on_passed, individual steps can be retried when they pass, but this requires explicit configuration for any step that someone might want to manually retry since it seems to default to false (or, at least, I don't see any buttons in the UI when it isn't configured). However, one can seemingly always "Rebuild" a whole build even if it is successful, meaning one can always effectively retry a single step by rerunning its whole build.

Given that it is possible, could the retry.manual.permit_on_passed default setting be flipped so that one doesn't have to waste the resources of doing a whole build when there's only a single step of interest?