List all busy times

curl --request GET \
  --url https://api.caspen.com/v1/busy_times

{
  "data": [
    {
      "id": "<string>",
      "location_id": "<string>",
      "practitioner_id": "<string>",
      "starts_at": "<string>",
      "ends_at": "<string>",
      "duration": 123,
      "name": "<string>",
      "note": "<string>",
      "created_at": "<string>"
    }
  ],
  "links": {
    "prev": "<string>",
    "next": "<string>"
  }
}