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/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))
 }