quic: don't run TestStreamsCreateConcurrency in synctest bubble

This test creates a pair of real UDP sockets; synctest doesn't work
well with real network connections and interactions between the
real network and synctest are probably causing flakiness.

Fixes golang/go#76510

Change-Id: I9e8a959e7d0077d8191ceb8284f6c338dd2688ab
Reviewed-on: https://go-review.googlesource.com/c/net/+/743402
Auto-Submit: Nicholas Husin <[email protected]>
Reviewed-by: Nicholas Husin <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Nicholas Husin <[email protected]>

Author: neild

quic/conn_streams_test.go

@@ -500,9 +500,6 @@ func testStreamsCreateAndCloseRemote(t *testing.T) {
 }
 
 func TestStreamsCreateConcurrency(t *testing.T) {
-	synctest.Test(t, testStreamsCreateConcurrency)
-}
-func testStreamsCreateConcurrency(t *testing.T) {
 	cli, srv := newLocalConnPair(t, &Config{}, &Config{})
 
 	srvdone := make(chan int)