Saves changes to name, summary, description and steps (which may
change shape) as the workflow's next version, recorded as the
caller's (createdBy). Allowed when the caller's permissions.canEdit
(the creator, a workspace Admin or Owner, or a super-admin on a
public workflow). A new version of an official workflow is not
official until verified again: officialVersion stays. Omitted
fields keep the latest version's. 409 when the workflow was saved
meanwhile. processors take the same shape as on create (including
an optional variant, checked against the pinned version: 400).