p2p: add channel buffers to avoid goroutine leaks in tests (#24929)

p2p/simulations/examples/ping-pong.go

@@ -139,7 +139,7 @@ const (
 func (p *pingPongService) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
 	log := p.log.New("peer.id", peer.ID())
 
-	errC := make(chan error)
+	errC := make(chan error, 1)
 	go func() {
 		for range time.Tick(10 * time.Second) {
 			log.Info("sending ping")

p2p/simulations/http_test.go

@@ -596,7 +596,7 @@ func TestHTTPSnapshot(t *testing.T) {
 	network, s := testHTTPServer(t)
 	defer s.Close()
 
-	var eventsDone = make(chan struct{})
+	var eventsDone = make(chan struct{}, 1)
 	count := 1
 	eventsDoneChan := make(chan *Event)
 	eventSub := network.Events().Subscribe(eventsDoneChan)