Problem:
jobwait() returns early if the job was stopped, but the job might have
pending callbacks on its event queue which are required to complete its
teardown. State such as term->closed might not be updated yet (by the
pending callbacks), so codepaths such as :bdelete think the job is still
running.
Solution:
Always flush the job's event queue before returning from jobwait().
ref #15349
3c081d0280