Removes a saved order template from Zuper. The template is untouched at the supplier and shows order_template_imported: false in Get Live Order Templates again, so you can save it again later (it gets a new order_template_uid). Products already imported from the template stay in your product catalog. The supplier provider must be CONNECTED; otherwise the request fails with 403. Admin only: the API key must belong to an admin user; other roles receive 405 Access Denied.