Update an override shift

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

{
  "data": {
    "id": "0b89ef38-591b-4e7a-8b96-4c6a6847a2ca",
    "type": "shifts",
    "attributes": {
      "schedule_id": "eab82a08-b3e6-4134-ad7d-0ff126251eab",
      "rotation_id": "9681285d-f647-4c34-805c-9017b9c5cbe8",
      "user_id": 468,
      "starts_at": "2025-12-24T03:27:27.000-08:00",
      "ends_at": "2025-12-24T11:27:27.000-08:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "b04ab417-5514-4eb4-b1fb-3e8e761d1527",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "468",
          "type": "users"
        }
      }
    }
  }
}