Letting a pull request run in whole deadlocks when its second arch
reaches the line behind another pull request: the run holds two
runners, the pull request in front waits for them, and the second arch
never gets to check. Each arch now waits on its own. A run with one
arch let in holds a runner only until that arch's app build is done,
and a run with both holds two until its universal build and tests
finish, so whoever is first in line always gets in eventually.
Co-authored-by: raistlin7447 <kris.austin@gmail.com>
