Background

As the monitoring plugin migrated away from nginx into a lightweight Go backend, changes in CMO were required to remove the ConfigMap that stored the nginx configuration.

In order to gracefully handle CMO upgrades the ConfigMap needs to be deleted if exists in 4.18. For 4.19 this log can be removed as the ConfigMap is not there anymore.

Previous PR: https://github.com/openshift/cluster-monitoring-operator/pull/2412

Outcomes

• If not already completed:
  • swap the Docker images in the `monitoring-plugin` to use the go binary
  • Update the CI for the `monitoring-plugin` to have FIPS checks similar to the other plugins (example)
• The logic for deleting the ConfigMap is removed from CMO for 4.19
• The code allowing for a backwards compatible image in CMO is adjusted or removed 

Steps

1. Remove the plugin nginx config ConfigMap deletion from CMO code