core: don't track jobs-finishing-during-reload explicitly

Memory management is borked for this, and moreover this is unnecessary
since f0831ed2, i.e. since coldplug() and catchup() are two different
concepts: the former restoring the state from before a reload, the
latter than adjusting it again to the actual status in effect after the
reload.

Fixes: #10716
Mostly reverts: #8803