Make async request order test more reliable.

Author: mdaigle

src/Microsoft.Data.SqlClient/tests/UnitTests/Microsoft/Data/SqlClient/ConnectionPool/ChannelDbConnectionPoolTest.cs

@@ -411,6 +411,10 @@ out internalConnection
                 new DbConnectionOptions("", null),
                 out recycledConnection
             );
+
+            // Gives time for the recycled connection to be queued before the failed request is initiated.
+            await Task.Delay(1000);
+
             DbConnectionInternal failedConnection = null;
             var exceeded2 = pool.TryGetConnection(
                 new SqlConnection("Timeout=1"),