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/discovery/mod.rs

@@ -1162,6 +1162,7 @@ mod tests {
                 syncnets: Default::default(),
             }),
             vec![],
+            false,
             &log,
         );
         Discovery::new(&keypair, &config, Arc::new(globals), &log)