When user projects monitoring feature is turned off the operator is cleaning up resources for user project monitoring, running multiple delete requests to apiserver.
This has several drawbacks:
* API Server can't cache DELETE requests, so it has to request etcd every time
* Audit log is flooded with "delete failed: object 'foo' not found" record

The function should first check that the object exists (GET requests are cachable) before issuing a DELETE request

    4.16.0

    Always

    1. Start 4.16.0
    2. Check audit log
    3.
    

    Audit log has messages like:
configmaps "serving-certs-ca-bundle" not found
servicemonitors.monitoring.coreos.com "thanos-ruler" not found

printed every few minutes

    No failed delete requests