kvnemisis: disable DRPC for tests

The 'TestKVNemesisMultiNode*' tests are showing flakiness when DRPC is
enabled, and this can be reproduced under stress. Until the root cause is
found, it's best to disable DRPC for these tests.

Release note: none
Epic: none

Author: shubhamdhama

pkg/kv/kvnemesis/main_test.go

@@ -30,7 +30,7 @@ func TestMain(m *testing.M) {
 	)()
 
 	defer serverutils.TestingGlobalDRPCOption(
-		base.TestDRPCEnabledRandomly,
+		base.TestDRPCDisabled,
 	)()
 
 	os.Exit(m.Run())