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": "0e547fd3-ede5-4069-94ae-6ed46d0f1161",
    "type": "shifts",
    "attributes": {
      "schedule_id": "a952bdd5-7272-4868-ad37-bcaf9958359e",
      "rotation_id": "529fa100-a4cf-4cfb-ac05-5efd710ca138",
      "starts_at": "2025-09-14T21:01:24.000-07:00",
      "ends_at": "2025-09-15T05:01:24.000-07:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "7c48b40b-fff1-4db2-968c-ebdf9f02e7b9",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "372",
          "type": "users"
        }
      }
    }
  }
}