Revert "try and catch issue with test."

This reverts commit 1d6fb2d960.

tests/Avalonia.Controls.UnitTests/TimePickerTests.cs

@@ -3,7 +3,6 @@ using System.Linq;
 using Avalonia.Controls.Shapes;
 using Avalonia.Controls.Templates;
 using Avalonia.Platform;
-using Avalonia.Threading;
 using Avalonia.UnitTests;
 using Avalonia.VisualTree;
 using Moq;
@@ -18,7 +17,6 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(Services))
             {
-                Assert.False(Dispatcher.UIThread.HasJobsWithPriority(0));
                 bool handled = false;
                 TimePicker timePicker = new TimePicker();
                 timePicker.SelectedTimeChanged += (s, e) =>