Details
Description
In BF-26723, it was found that the ReshardingCoordinatorService relies on the executor to emplace promises after running _isReshardingOpRedundant(). If the executor is shut down as part of stepDown(), the `onCompletion` in chain is not run that causes unfulfilled promises resulting in invariant failure when the old primary instances are destroyed. One fix is to run the cleanup on a different executor.