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": "abe1f68f-c02f-5251-9559-a2d2ecb0dd94",
    "type": "shifts",
    "attributes": {
      "schedule_id": "8055cf77-9b3f-40e8-b8fe-e7900d038a78",
      "rotation_id": "bf0f1406-4295-440b-9daa-139da81b012b",
      "user_id": 465,
      "starts_at": "2025-12-05T15:27:42.000-08:00",
      "ends_at": "2025-12-05T23:27:42.000-08:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "286624e7-a017-4063-9121-148944719188",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "465",
          "type": "users"
        }
      }
    }
  }
}