Retrieves a heartbeat

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

{
  "data": {
    "id": "633282ad-c0b8-47ac-87bf-2bc98ba668b8",
    "type": "heartbeats",
    "attributes": {
      "slug": "sit-veritatis-non-ipsa",
      "name": "Sit veritatis non ipsa.",
      "description": "Dignissimos non aut in.",
      "alert_summary": "API is down",
      "alert_urgency_id": "27c51af6-ae9e-4cb9-876a-d4c0edf6c5ea",
      "interval": 9,
      "interval_unit": "seconds",
      "notification_target_id": "161",
      "notification_target_type": "User",
      "ping_url": "http://localhost:3001/v1/heartbeats/633282ad-c0b8-47ac-87bf-2bc98ba668b8/ping",
      "secret": "heartbeat_d6a4097387d86971fb833bf6e05a8a5381abd99acd22229aafe872b645987580",
      "last_pinged_at": null,
      "expires_at": null,
      "enabled": false,
      "status": "waiting",
      "updated_at": "2025-07-23T05:28:53.814-07:00",
      "created_at": "2025-07-23T05:28:53.814-07:00"
    }
  }
}