update libp2p (#4864)

## Issue Addressed

updates libp2p to the latest version and uses the new `SwarmBuilder`. Superseeds https://github.com/sigp/lighthouse/pull/4695/
CC @mxinden I don't think we can use both `bandwidth_loggers` with the new syntax right?

beacon_node/lighthouse_network/src/service/mod.rs

@@ -29,10 +29,10 @@ use libp2p::gossipsub::{
     self, IdentTopic as Topic, MessageAcceptance, MessageAuthenticity, MessageId, PublishError,
     TopicScoreParams,
 };
-use libp2p::identify;
 use libp2p::multiaddr::{Multiaddr, Protocol as MProtocol};
-use libp2p::swarm::{Swarm, SwarmBuilder, SwarmEvent};
+use libp2p::swarm::{Swarm, SwarmEvent};
 use libp2p::PeerId;
+use libp2p::{identify, SwarmBuilder};
 use slog::{crit, debug, info, o, trace, warn};
 use std::path::PathBuf;
 use std::pin::Pin;
@@ -365,8 +365,7 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
             }
         };
 
-        let (swarm, bandwidth) = {
-            // Set up the transport - tcp/ws with noise and mplex
+        // Set up the transport - tcp/quic with noise and mplex
         let (transport, bandwidth) =
             build_transport(local_keypair.clone(), !config.disable_quic_support)
                 .map_err(|e| format!("Failed to build transport: {:?}", e))?;
@@ -379,21 +378,21 @@ impl<AppReqId: ReqId, TSpec: EthSpec> Network<AppReqId, TSpec> {
             }
         }
 
-            // sets up the libp2p connection limits
-
-            (
-                SwarmBuilder::with_executor(
-                    transport,
-                    behaviour,
-                    local_peer_id,
-                    Executor(executor),
+        // sets up the libp2p swarm.
+        let swarm = SwarmBuilder::with_existing_identity(local_keypair)
+            .with_tokio()
+            .with_other_transport(|_key| transport)
+            .expect("infalible")
+            .with_behaviour(|_| behaviour)
+            .expect("infalible")
+            .with_swarm_config(|_| {
+                libp2p::swarm::Config::with_executor(Executor(executor))
+                    .with_notify_handler_buffer_size(
+                        std::num::NonZeroUsize::new(7).expect("Not zero"),
                     )
-                .notify_handler_buffer_size(std::num::NonZeroUsize::new(7).expect("Not zero"))
-                .per_connection_event_buffer_size(4)
-                .build(),
-                bandwidth,
-            )
-        };
+                    .with_per_connection_event_buffer_size(4)
+            })
+            .build();
 
         let mut network = Network {
             swarm,

beacon_node/lighthouse_network/src/service/utils.rs

@@ -88,7 +88,7 @@ pub fn build_transport(
     };
 
     // Enables DNS over the transport.
-    let transport = libp2p::dns::TokioDnsConfig::system(transport)?.boxed();
+    let transport = libp2p::dns::tokio::Transport::system(transport)?.boxed();
 
     Ok((transport, bandwidth))
 }