As part of #47904, we'll be introducing tenant destruction. It's tempting to make this is a synchronous operation that blows away all data in a tenant's keyspace immediately. This would probably work for the scale we're originally intending to support, but it's not a great solution in the long run.

We expect tenants to grow to arbitrarily large sizes, so we'll likely want to schedule tenant destruction as a long-running GC job in the system-tenants keyspace.