Deletes one of the caller's named Reasons, as Delete in the Reason app does: it leaves every Reason list, its Loops are deleted so nothing scheduled or triggered runs for it, its own Slack app is removed, and its conversation is archived with its history. The Sessions it started stay where they are. Nothing restores it. Only its owner deletes it, and the main Reason is never deleted (409 main_reason_kept). archiveReason is the same operation under its older name.

_{Scope: run}