libtracker-miner: Dispose cached events on MONITOR_EVENT_DELETED

I don't know if this is possible, but in case that happens we should
drop the event either way, and neutralize CREATED+DELETED events early
on.
1 job from wip/carlosg/fix-changes-done-hint-handling in 1 minute and 54 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #234651
test-fedora-latest

00:01:54