storage: deflake TestRaftRemoveRace
storage: deflake TestRaftRemoveRace

Changed Store.deadReplicas() to only return corrupt replicas, not all
replicas which have been marked as destroyed. The latter includes
replicas that have been removed and which we can re-add to the store
without problem.

Fixes #10235

vaibhavarora/cockroach,veteranlu/cockroach,vaibhavarora/cockroach,petermattis/cockroach,paperstreet/cockroach,maxlang/cockroach,glycerine/cockroach,glycerine/cockroach,vaibhavarora/cockroach,glycerine/cockroach,petermattis/cockroach,vaibhavarora/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,petermattis/cockroach,glycerine/cockroach,veteranlu/cockroach,maxlang/cockroach,paperstreet/cockroach,glycerine/cockroach,petermattis/cockroach,petermattis/cockroach,paperstreet/cockroach,veteranlu/cockroach,maxlang/cockroach,paperstreet/cockroach,maxlang/cockroach,glycerine/cockroach,maxlang/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,maxlang/cockroach,veteranlu/cockroach,glycerine/cockroach,paperstreet/cockroach,veteranlu/cockroach,maxlang/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,glycerine/cockroach,paperstreet/cockroach,vaibhavarora/cockroach,veteranlu/cockroach,paperstreet/cockroach,petermattis/cockroach,petermattis/cockroach,maxlang/cockroach,petermattis/cockroach