Updates a webhook subscription in place; fields you omit keep their current values. Only description, event_trigger, event_trigger_filters, request_type, request_url, header_json, body_payload_type, body_payload_json and enabled are applied — any other key in the body is ignored, and a body with none of them is rejected with 400. The subscription's name cannot be changed with this call: name is ignored and webhook_name is rejected with 400. An ID that belongs to another account is answered with 404 and nothing is written. The response body is an empty object; read the subscription back to see its new state.