Updated Description

The task to submit range deletions was scheduled using an arbitrary sharding executor to avoid deadlocks in unit tests that involve metadata refreshes. If the unit tests use mocks for the refreshes instead, the deletions can be scheduled on the fixed sharding executor while still avoiding deadlocks.

Original Description

The task to submit range deletions may need to force a refresh if the filtering metadata is unknown, so we should add a way for the task to wait for the refresh without blocking in a thread pool thread.