Release builds for local cluster tests (#5891)

* Release builds for test

* Remove setting thread count in local cluster

* Increase timeout

* Move local cluster to separate job

* Extract out local cluster test from bench-tps

* Make local cluster inaccessible from outside crate

* Update test-stable.sh to exclude local_cluster in stable, include it in local-cluster CI job

* Move bench-exchange to local cluster

* Remove local cluster from coverage

local_cluster/src/local_cluster.rs

@@ -10,7 +10,6 @@ use solana_core::{
     service::Service,
     validator::{Validator, ValidatorConfig},
 };
-use solana_rayon_threadlimit::set_thread_count;
 use solana_sdk::{
     client::SyncClient,
     clock::DEFAULT_TICKS_PER_SLOT,
@@ -117,8 +116,6 @@ impl LocalCluster {
     }
 
     pub fn new(config: &ClusterConfig) -> Self {
-        set_thread_count(1);
-
         assert_eq!(config.validator_configs.len(), config.node_stakes.len());
         let leader_keypair = Arc::new(Keypair::new());
         let leader_pubkey = leader_keypair.pubkey();