text: Title: Alerting services deprecated configuration cleanup
  Body: Below is a list of deprecated configs that should be cleaned up when telemetry from https://github.com/elastic/kibana/issues/108716 shows usage is below 1% or deprecated for > 2.5 years.
  
  - Remove deprecated `xpack.actions.whitelistedHosts` from #76325
  - Remove deprecated `xpack.alerts.healthCheck` from https://github.com/elastic/kibana/pull/92898
  - Remove deprecated `xpack.alerts.invalidateApiKeysTask.interval` from https://github.com/elastic/kibana/pull/92898
  - Remove deprecated `xpack.alerts.invalidateApiKeysTask.removalDelay` from https://github.com/elastic/kibana/pull/92898