Update incident_sub_status

curl --request PUT \
  --url https://api.rootly.com/v1/incident_sub_statuses/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/vnd.api+json' \
  --data '{
  "data": {
    "type": "incident_sub_statuses",
    "attributes": {
      "sub_status_id": "<string>",
      "assigned_at": "<string>",
      "assigned_by_user_id": 123
    }
  }
}'

{
  "data": {
    "id": "290bd3d8-512f-4c22-a9b1-c799b39cb443",
    "type": "incident_sub_statuses",
    "attributes": {
      "sub_status_id": "9af8adf9-15ea-4f16-9844-6a56d91b2b2b",
      "incident_id": "9d27cfcd-9fed-40f1-9063-202247fc9503",
      "assigned_at": "2025-11-18T19:05:09.000-08:00",
      "assigned_by_user_id": 348
    },
    "relationships": {
      "sub_status": {
        "data": {
          "id": "9af8adf9-15ea-4f16-9844-6a56d91b2b2b",
          "type": "sub_statuses"
        }
      },
      "assigned_by_user": {
        "data": {
          "id": "348",
          "type": "users"
        }
      }
    }
  }
}