kvnemesis: use ReplicationManual

[tbg]

Describe the problem

In #89477, TestKVNemesisMultiNode was (accidentally) switched to use ReplicationAuto instead of ReplicationManual, meaning that the TestCluster will upreplicate and also have the replicate queue active throughout the run.

We should decide whether that's desirable and if not, undo this change.

kvnemesis does perform manual replication changes, so manual seems preferrable to preserve as much determinism as possible.

kvnemesis also performs random zone config changes, which I thought was an argument for keeping the replicate queue active, but it turns out that at the time of writing, the only zone cfg change it can make is toggling global reads, which is independent of the replicate queue being active:

cockroach/pkg/kv/kvnemesis/generator.go

Lines 914 to 916 in 97054a0

	func changeZone(changeType ChangeZoneType) Operation {
	return Operation{ChangeZone: &ChangeZoneOperation{Type: changeType}}
	}

Jira issue: CRDB-22630

[blathers-crl]

cc @cockroachdb/test-eng

[tbg]

@srosenberg you mentioned you'd send a PR with small fixes to kvnemesis anyway, mind rolling this into that? You just need to add the ReplicationMode back in here:

cockroach/pkg/kv/kvnemesis/kvnemesis_test.go

Line 57 in 1175940

ServerArgs: base.TestServerArgs{

[srosenberg]

you mentioned you'd send a PR with small fixes to kvnemesis anyway, mind rolling this into that?

Sure thing, thanks for creating the issue. I have a few small fixes (mostly typos in comments), but I plan to go through the code in more depth over the next few days. I'll send a PR with whatever else I find plus ReplicationManual.