See parent issue https://issues.redhat.com/browse/MON-4393

When ocp 4.21 or above is detected, our servicemonitors should use EndpointSlice instead of Endpoint, which is a deprecated API

This should be verified by looking at the generated ServiceMonitor objects, which will or won't use "ServiceDiscoveryRole" depending on ocp version. Apart from that, there should not be any visible outcome, we expect metrics to be generated "as usual".