In #78608 we began checking the io overload (via a similar but not identical stat which should be replaced #85084) for load based (store rebalancer) replica rebalancing.

This however didn't extend to lease transfers: FollowTheWorkload, LeaseCountConvergence and LoadConvergence.

This issue is to extend the io overload checks to apply to lease transfer targets in the allocator.

Jira issue: CRDB-24157