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": "a3f9c9e9-3778-4483-b3fb-9876fa2e5118",
    "type": "shifts",
    "attributes": {
      "schedule_id": "8c12bbe8-1efb-4f87-9a25-8db569af0eca",
      "rotation_id": "b15467b7-9424-4637-b3fc-092ba0e9ae5b",
      "starts_at": "2025-05-29T11:46:52.000-07:00",
      "ends_at": "2025-05-29T19:46:52.000-07:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "820469e8-2d63-4d88-bb65-9c3478407d51",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "345",
          "type": "users"
        }
      }
    }
  }
}