Update schedule rotation user

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

{
  "data": {
    "id": "bae852e4-f9dd-4015-a704-03130aa2f5fa",
    "type": "schedule_rotation_users",
    "attributes": {
      "schedule_rotation_id": "4c382f17-25d7-4dc3-a816-e2e33f2034f7",
      "user_id": 521,
      "position": 2,
      "created_at": "2025-12-19T18:18:09.730-08:00",
      "updated_at": "2025-12-19T18:18:09.736-08:00"
    }
  }
}