Revert "fix(cassandra-harry): disable nemesis"

now we proven the the nemesis mostly works,
beside scylladb/scylladb#10598 that still under
investigation

This reverts commit 820d561.

test-cases/longevity/longevity-harry-2h.yaml

@@ -9,7 +9,7 @@ instance_type_db: 'i3.large'
 
 aws_root_disk_size_loader: 80 # enlarge loader disk, cause of cassandra-harry operation.log that can't be disabled
 
-nemesis_class_name: 'NoOpMonkey'
+nemesis_class_name: 'SisyphusMonkey'
 nemesis_seed: '001'
 nemesis_interval: 2
 ssh_transport: 'libssh2'