feat: enable circuit relay transport

this should have been enabled by default but doesn't seem to have been

Author: dennis-tra

discv5/driver_crawler.go

@@ -297,6 +297,7 @@ func newLibp2pHost(version string) (host.Host, error) {
 		libp2p.Muxer(yamux.ID, yamux.DefaultTransport),
 		libp2p.DisableMetrics(),
 		libp2p.ConnectionManager(connmgr.NullConnMgr{}),
+		libp2p.EnableRelay(), // enable the relay transport
 	)
 	if err != nil {
 		return nil, fmt.Errorf("new libp2p host: %w", err)

libp2p/driver_crawler.go

@@ -203,5 +203,6 @@ func newLibp2pHost(version string) (host.Host, error) {
 		libp2p.UserAgent("nebula/"+version),
 		libp2p.ConnectionManager(connmgr.NullConnMgr{}),
 		libp2p.DisableMetrics(),
+		libp2p.EnableRelay(), // enable the relay transport
 	)
 }