Address lint issues as a result of libp2p deprecations and tidy go mod

Address staticcheck issues caused by deprecated APIs and `go mod tidy`.

node/config/load.go

@@ -33,7 +33,7 @@ func FromFile(path string, def interface{}) (interface{}, error) {
 // FromReader loads config from a reader instance.
 func FromReader(reader io.Reader, def interface{}) (interface{}, error) {
 	cfg := def
-	_, err := toml.DecodeReader(reader, cfg)
+	_, err := toml.NewDecoder(reader).Decode(cfg)
 	if err != nil {
 		return nil, err
 	}

node/impl/net/net.go

@@ -11,9 +11,9 @@ import (
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
 	"github.com/libp2p/go-libp2p-core/protocol"
-	swarm "github.com/libp2p/go-libp2p-swarm"
 	basichost "github.com/libp2p/go-libp2p/p2p/host/basic"
 	"github.com/libp2p/go-libp2p/p2p/net/conngater"
+	"github.com/libp2p/go-libp2p/p2p/net/swarm"
 	"github.com/libp2p/go-libp2p/p2p/protocol/ping"
 	ma "github.com/multiformats/go-multiaddr"
 	"go.uber.org/fx"

node/modules/lp2p/relay.go

@@ -6,7 +6,7 @@ import (
 	"github.com/libp2p/go-libp2p"
 	coredisc "github.com/libp2p/go-libp2p-core/discovery"
 	"github.com/libp2p/go-libp2p-core/routing"
-	discovery "github.com/libp2p/go-libp2p-discovery"
+	routingdisc "github.com/libp2p/go-libp2p/p2p/discovery/routing"
 )
 
 func NoRelay() func() (opts Libp2pOpts, err error) {
@@ -24,5 +24,5 @@ func Discovery(router BaseIpfsRouting) (coredisc.Discovery, error) {
 		return nil, fmt.Errorf("no suitable routing for discovery")
 	}
 
-	return discovery.NewRoutingDiscovery(crouter), nil
+	return routingdisc.NewRoutingDiscovery(crouter), nil
 }