Remove obsolete leases

Motivation

Occurred that obsolete leases (expired leases for removed replication groups) aren't dropped themselves. Despite the fact that it's generally a leak and thus incorrect, some tests like ItSqlLogicTest may suffer from this.

Definition of Done

Obsolete leases are removed from the meta storage and thus no longer processed.

Implementation Notes

I believe that

// Remove all expired leases that are no longer present in assignments.
renewedLeases.entrySet().removeIf(e -> e.getValue().getExpirationTime().before(now)
  && !currentAssignmentsReplicationGroupIds.contains(e.getKey()));

in 

org.apache.ignite.internal.placementdriver.LeaseUpdater.Updater#updateLeaseBatchInternal

should do the trick.