Fix data race on locally closing the connection

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3Connection.cs

@@ -197,6 +197,10 @@ public async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, lon
                         }
                     }
                 }
+                // Swallow any exceptions caused by the connection being closed locally or even disposed due to a race.
+                // Since quicStream will stay `null`, the code below will throw appropriate exception to retry the request.
+                catch (ObjectDisposedException) { }
+                catch (QuicException e) when (!(e is QuicConnectionAbortedException)) { }
                 finally
                 {
                     if (HttpTelemetry.Log.IsEnabled() && queueStartingTimestamp != 0)