Add a flag to disable peer scoring (#4135)

## Issue Addressed

N/A

## Proposed Changes

Adds a flag for disabling peer scoring. This is useful for local testing and testing small networks for new features.

beacon_node/lighthouse_network/src/service/mod.rs

@@ -171,6 +171,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
                     .iter()
                     .map(|x| PeerId::from(x.clone()))
                     .collect(),
+                config.disable_peer_scoring,
                 &log,
             );
             Arc::new(globals)