Enable --web.enable-admin-api for user-workload-monitoring Prometheus in RHOCP 4

Issue

• Not able to delete time series in the User Workload Monitoring Prometheus as it's not enabled the flag --web.enable-admin-api that controls access to the administrative HTTP API
• Returned an "unavailable" message when running administrative tasks against the User Workload Monitoring Prometheus HTTP API

• It's desired to delete time series in the User Workload Monitoring Prometheus, but it returns the error:

  {
  "status": "error",
  "errorType": "unavailable",
  "error": "admin APIs disabled"
  }