Make JobQueueGroup::push() update the queuesHaveJobs() cache
This makes it so jobs can run sooner with $wgJobRunRate
Bug: T145206
Change-Id: Ia7673f51312f90a696fa056bd3daf7f3f440782b
(cherry picked from commit 6f9a246d25b29d406e68e366e707822f14be8a2d)