fix testing tool and remove unused const

management/server/http/testing/testing_tools/tools.go

@@ -118,7 +118,7 @@ func BuildApiBlackBoxWithDBState(t TB, sqlFile string, expectedPeerUpdate *serve
 		t.Fatalf("Failed to create metrics: %v", err)
 	}
 
-	peersUpdateManager := server.NewPeersUpdateManager(nil)
+	peersUpdateManager := server.NewPeersUpdateManager(metrics)
 	updMsg := peersUpdateManager.CreateChannel(context.Background(), TestPeerId)
 	done := make(chan struct{})
 	if validateUpdate {

management/server/peer.go

@@ -906,6 +906,9 @@ func (am *DefaultAccountManager) LoginPeer(ctx context.Context, login types.Peer
 
 		if updateRemotePeers || isStatusChanged || (isPeerUpdated && len(postureChecks) > 0) {
 			err = transaction.IncrementNetworkSerial(ctx, store.LockingStrengthUpdate, accountID)
+			if err != nil {
+				return fmt.Errorf("failed to increment network serial: %w", err)
+			}
 		}
 
 		return nil

management/server/updatechannel.go

@@ -12,8 +12,6 @@ import (
 	"github.com/netbirdio/netbird/management/server/types"
 )
 
-const channelBufferSize = 2
-
 type UpdateMessage struct {
 	Update     *proto.SyncResponse
 	NetworkMap *types.NetworkMap