multi: use the "errors" package everywhere

Replace all usages of the "github.com/go-errors/errors" and
"github.com/pkg/errors" packages with the standard lib's "errors"
package. This ensures that error wrapping and `errors.Is` checks will
work as expected.

discovery/gossiper_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	prand "math/rand"
 	"net"
@@ -20,7 +21,6 @@ import (
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
-	"github.com/go-errors/errors"
 	"github.com/lightninglabs/neutrino/cache"
 	"github.com/lightningnetwork/lnd/batch"
 	"github.com/lightningnetwork/lnd/chainntnfs"

discovery/validation_barrier.go

@@ -1,11 +1,11 @@
 package discovery
 
 import (
+	"errors"
 	"fmt"
 	"sync"
 	"sync/atomic"
 
-	"github.com/go-errors/errors"
 	"github.com/lightningnetwork/lnd/fn/v2"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/routing/route"