rosa-sts-ovn dags must wait for nodes to update before running benchmarks

[afcollins]

node-density fails because p99 latency is > 5s. The reason the latency is so high is bc worker nodes are still being updated when the test starts.

We must ensure the worker MCP is completely updated (READY == UPDATED).
We can speed up this process by setting maxUnavailable=100%.

It would also be a plus to pause all MCPs after the cluster and all day2 operations are complete, so any platform maintenance will not disrupt the tests.

Recent failure log: msg="❗ P99 Ready latency (11.52s) higher than configured threshold: 5s

I thought we could increase or remove the pod-threshold from the test, but that would give us bad data and increase confusion when looking at results. It is best to fix this during install/postinstall tasks up front.