What is the best way to delete many shifts?

Context: We need to performance test our sync engine which pulls humanity shifts. As part of this we require setup/cleanup.

Problem: When deleting shifts we can only delete one at at time by providing shift_id, when trying to delete many shifts 429 (too many requests) are returned. Is there a way to delete many shifts at once? i.e. provide an object or array of shift_ids to be deleted.