Use the mesh_n value from NetworkLoad for PeerScoreSettings (#5013)

* Build `gs_config` and use the `mesh_n` config for `PeerScoreSettings`

* Remove unused imports

* Merge branch 'unstable' into peer-score-settings

# Conflicts:
#	beacon_node/lighthouse_network/src/config.rs
#	beacon_node/lighthouse_network/src/service/gossipsub_scoring_parameters.rs
#	beacon_node/lighthouse_network/src/service/mod.rs

beacon_node/lighthouse_network/src/config.rs

@@ -69,10 +69,6 @@ pub struct Config {
     /// Target number of connected peers.
     pub target_peers: usize,
 
-    /// Gossipsub configuration parameters.
-    #[serde(skip)]
-    pub gs_config: gossipsub::Config,
-
     /// Discv5 configuration parameters.
     #[serde(skip)]
     pub discv5_config: discv5::Config,
@@ -278,12 +274,6 @@ impl Default for Config {
             .join(DEFAULT_BEACON_NODE_DIR)
             .join(DEFAULT_NETWORK_DIR);
 
-        // Note: Using the default config here. Use `gossipsub_config` function for getting
-        // Lighthouse specific configuration for gossipsub.
-        let gs_config = gossipsub::ConfigBuilder::default()
-            .build()
-            .expect("valid gossipsub configuration");
-
         // Discv5 Unsolicited Packet Rate Limiter
         let filter_rate_limiter = Some(
             discv5::RateLimiterBuilder::new()
@@ -336,7 +326,6 @@ impl Default for Config {
             enr_quic6_port: None,
             enr_tcp6_port: None,
             target_peers: 100,
-            gs_config,
             discv5_config,
             boot_nodes_enr: vec![],
             boot_nodes_multiaddr: vec![],