curl --request GET \
  --url https://api.coval.dev/v1/metrics/{metric_id}/threshold \
  --header 'X-API-Key: <api-key>'

{
  "threshold": {
    "name": "metrics/abc123def456ghi789jklm/threshold",
    "target_float_upper": 0.8,
    "target_float_lower": 123,
    "target_values": [
      "<string>"
    ],
    "create_time": "2023-11-07T05:31:56Z",
    "update_time": "2023-11-07T05:31:56Z"
  }
}