Description:

Describe the desired behavior, what scenario it enables and how it
would be used.

Having initially deployed the GatewayClass with parametersRef, the user can later edit it and remove the envoy proxy resource from parametersRef.
It would be good to check for such updates and clean up the unused resource from the cluster.

[optional Relevant Links:]

Any extra documentation required to understand the issue.

It could be another follow-up to these PRs

• Add Support for Managing the Envoy Proxy Service #648
• Finalize EnvoyProxy #865