OSS cluster API is now always enabled ( we do the setup stage for cluster always )

[filipecosta90]

$ ./pubsub-sub-bench 
2023/06/26 08:58:22 pubsub-sub-bench (git_sha1:862e101546c7238176ea5db2cc2875460b479076)
2023/06/26 08:58:22 Total subcriptions: 100. Subscriptions per node 100. Total messages: 0
2023/06/26 08:58:22 Will use a subscriber prefix of: channel-<channel id>
2023/06/26 08:58:22 Setting per Node pool size of 100 given you haven't specified a value and we have 100 Subscriptions per node. You can control this option via --pool_size=<value>
2023/06/26 08:58:22 Reloading cluster state given we've changed pool size.
2023/06/26 08:58:22 ERR This instance has cluster support disabled