Goldpinger does not log failed pings

[benruland]

Describe the bug
The Goldpinger logging does not log warnings, when a ping fails. This is expected from this line:

p.logger.Warn("Ping returned error", zap.Duration("responseTime", responseTime), zap.Error(err))

https://github.com/bloomberg/goldpinger/blob/master/pkg/goldpinger/pinger.go#L151C3-L151C99

To Reproduce
Steps to reproduce the behavior:

1. Deploy Goldpinger with the provided Helm Chart
2. Shutdown one node
3. GUI shows, that all other Goldpinger pods can not reach that node
4. Logfile of any goldpinger pod is empty, besides the startup output:

{"level":"info","ts":"2025-09-03T09:56:37.642Z","caller":"goldpinger/main.go:116","message":"Goldpinger","version":"v3.10.2","build":"Mon Nov 11 14:33:52 UTC 2024"}
{"level":"info","ts":"2025-09-03T09:56:37.643Z","caller":"goldpinger/main.go:127","message":"Kubeconfig not specified, trying to use in cluster config"}
{"level":"info","ts":"2025-09-03T09:56:37.739Z","caller":"goldpinger/main.go:153","message":"PodIP not set: pinging all pods"}
{"level":"info","ts":"2025-09-03T09:56:37.739Z","caller":"goldpinger/main.go:156","message":"--ping-number set to 0: pinging all pods"}
{"level":"info","ts":"2025-09-03T09:56:37.840Z","caller":"goldpinger/main.go:189","message":"All good, starting serving the API"}

Expected behavior
It is expected to see failed pings in the goldpinger logfiles, in order to diagnose failed pings after they occured (e.g. at night).

Additional information
The zapConfig was not altered:

{
  "level": "info",
  "encoding": "json",
  "outputPaths": [
      "stdout"
  ],
  "errorOutputPaths": [
      "stderr"
  ],
  "initialFields": {
  },
  "encoderConfig": {
      "messageKey": "message",
      "levelKey": "level",
      "levelEncoder": "lowercase",
      "timeKey": "ts",
      "timeEncoder": "ISO8601",
      "callerKey": "caller",
      "callerEncoder": "Short"
  }
}

Environment (please complete the following information):

• OpenShift 4.16
• Goldpinger 3.10.2