Retrieves a schedule shifts

curl --request GET \
  --url https://api.rootly.com/v1/schedules/{id}/shifts \
  --header 'Authorization: Bearer <token>'

{
  "data": [
    {
      "id": "6d6bab8d-2d93-4cf7-b6a3-c7b391598dcb",
      "type": "shifts",
      "attributes": {
        "schedule_id": "b656c41e-9dd0-4b0e-b683-0470d1a0e1bc",
        "rotation_id": "75a15d53-0e83-4630-a54c-04601d1e265a",
        "user_id": 905,
        "starts_at": "2026-01-20T00:26:21.000-08:00",
        "ends_at": "2026-01-20T04:26:21.000-08:00",
        "is_override": true
      },
      "relationships": {
        "shift_override": {
          "data": null
        },
        "user": {
          "data": {
            "id": "905",
            "type": "users"
          }
        }
      }
    },
    {
      "id": "0c96557c-da03-5a8d-b6c0-cc3158295017",
      "type": "shifts",
      "attributes": {
        "schedule_id": "b656c41e-9dd0-4b0e-b683-0470d1a0e1bc",
        "rotation_id": "740b057b-9bbd-4750-a9b3-8efab6753bfb",
        "user_id": 909,
        "starts_at": "2026-01-20T05:26:22.000-08:00",
        "ends_at": "2026-01-20T09:26:22.000-08:00",
        "is_override": false
      },
      "relationships": {
        "shift_override": {
          "data": null
        },
        "user": {
          "data": {
            "id": "909",
            "type": "users"
          }
        }
      }
    }
  ]
}