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": "e5d2c68a-69af-4f6a-a5ba-956a49fcead2",
    "type": "shifts",
    "attributes": {
      "schedule_id": "e9a96cf4-4e73-4d79-9827-c68fd2e26dff",
      "rotation_id": "16a7c8e4-eaa3-4c2a-b8b6-ed2d52246166",
      "starts_at": "2025-06-26T06:22:54.000-07:00",
      "ends_at": "2025-06-26T14:22:54.000-07:00",
      "is_override": true
    },
    "relationships": {
      "shift_override": {
        "data": {
          "id": "ebfd373a-b8d5-47f8-b1e9-8278aebc46a8",
          "type": "shift_overrides"
        }
      },
      "user": {
        "data": {
          "id": "355",
          "type": "users"
        }
      }
    }
  }
}