Bump libp2p to address inconsistency in mesh peer tracking (#2493)

## Issue Addressed

- Resolves #2457
- Resolves #2443

## Proposed Changes

Target the (presently unreleased) head of `libp2p/rust-libp2p:master` in order to obtain the fix from https://github.com/libp2p/rust-libp2p/pull/2175.

Additionally:

- `libsecp256k1` needed to be upgraded to satisfy the new version of `libp2p`.
- There were also a handful of minor changes to `eth2_libp2p` to suit some interface changes.
- Two `cargo audit --ignore` flags were remove due to libp2p upgrades.

## Additional Info
 
 NA

beacon_node/eth2_libp2p/src/discovery/enr_ext.rs

@@ -203,7 +203,7 @@ impl CombinedKeyPublicExt for CombinedPublicKey {
                     libp2p::core::identity::secp256k1::PublicKey::decode(&pk_bytes)
                         .expect("valid public key"),
                 );
-                PeerId::from_public_key(libp2p_pk)
+                PeerId::from_public_key(&libp2p_pk)
             }
             Self::Ed25519(pk) => {
                 let pk_bytes = pk.to_bytes();
@@ -211,7 +211,7 @@ impl CombinedKeyPublicExt for CombinedPublicKey {
                     libp2p::core::identity::ed25519::PublicKey::decode(&pk_bytes)
                         .expect("valid public key"),
                 );
-                PeerId::from_public_key(libp2p_pk)
+                PeerId::from_public_key(&libp2p_pk)
             }
         }
     }
@@ -283,7 +283,7 @@ mod tests {
         let libp2p_sk = libp2p::identity::secp256k1::SecretKey::from_bytes(sk_bytes).unwrap();
         let secp256k1_kp: libp2p::identity::secp256k1::Keypair = libp2p_sk.into();
         let libp2p_kp = Keypair::Secp256k1(secp256k1_kp);
-        let peer_id = libp2p_kp.public().into_peer_id();
+        let peer_id = libp2p_kp.public().to_peer_id();
 
         let enr = discv5::enr::EnrBuilder::new("v4")
             .build(&secret_key)
@@ -304,7 +304,7 @@ mod tests {
         let libp2p_sk = libp2p::identity::ed25519::SecretKey::from_bytes(sk_bytes).unwrap();
         let ed25519_kp: libp2p::identity::ed25519::Keypair = libp2p_sk.into();
         let libp2p_kp = Keypair::Ed25519(ed25519_kp);
-        let peer_id = libp2p_kp.public().into_peer_id();
+        let peer_id = libp2p_kp.public().to_peer_id();
 
         let enr = discv5::enr::EnrBuilder::new("v4").build(&keypair).unwrap();
         let node_id = peer_id_to_node_id(&peer_id).unwrap();

beacon_node/eth2_libp2p/src/rpc/handler.rs

@@ -59,6 +59,7 @@ type InboundProcessingOutput<TSpec> = (
 type HandlerEvent<T> = Result<RPCReceived<T>, HandlerErr>;
 
 /// An error encountered by the handler.
+#[derive(Debug)]
 pub enum HandlerErr {
     /// An error occurred for this peer's request. This can occur during protocol negotiation,
     /// message passing, or if the handler identifies that we are sending an error response to the peer.

beacon_node/eth2_libp2p/src/service.rs

@@ -143,7 +143,7 @@ impl<TSpec: EthSpec> Service<TSpec> {
                 .with_max_established_outgoing(Some(
                     (config.target_peers as f32 * (1.0 + PEER_EXCESS_FACTOR)) as u32,
                 ))
-                .with_max_established_total(Some(
+                .with_max_established(Some(
                     (config.target_peers as f32 * (1.0 + PEER_EXCESS_FACTOR)) as u32,
                 ))
                 .with_max_established_per_peer(Some(MAX_CONNECTIONS_PER_PEER));