Unstable unit test: System.Windows.Forms.UITests.ButtonTests.Button_CancelButton_EscapeClicksCancelButtonAsync

[LeafShi1]

Related https://github.com/dotnet/winforms/issues/11227

Test

System.Windows.Forms.UITests.ButtonTests.Button_CancelButton_EscapeClicksCancelButtonAsync

Issue description

The case failed in X64 unit tests, the failure link:

• #20240430.11 • Enable nullability in DesignerWindowTarget (#11279)
• #20240427.4 • [main] Update dependencies from dotnet/runtime (#11281)

Error Message:

• In X64 unit:
  • Assert.Equal() Failure: Values differ Expected: Cancel Actual: None

Stack trace:

   at System.Windows.Forms.UITests.ButtonTests.<Button_CancelButton_EscapeClicksCancelButtonAsync>b__4_0(Form form, Button button) in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ButtonTests.cs:line 101
   at System.Windows.Forms.UITests.ControlTestBase.<>c__DisplayClass32_0`1.<<RunFormAsync>b__0>d.MoveNext() in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/Infra/ControlTestBase.cs:line 315
--- End of stack trace from previous location ---
   at Microsoft.VisualStudio.Threading.JoinableTask.JoinAsync(CancellationToken cancellationToken)
   at System.Windows.Forms.UITests.ControlTestBase.RunFormAsync[T](Func`1 createDialog, Func`3 testDriverAsync) in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/Infra/ControlTestBase.cs:line 339
   at System.Windows.Forms.UITests.ControlTestBase.RunSingleControlTestAsync[T](Func`3 testDriverAsync, Func`1 createControl, Func`1 createForm) in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/Infra/ControlTestBase.cs:line 246
   at System.Windows.Forms.UITests.ButtonTests.RunTestAsync(Func`3 runTest) in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ButtonTests.cs:line 385
   at System.Windows.Forms.UITests.ButtonTests.Button_CancelButton_EscapeClicksCancelButtonAsync() in /_/src/System.Windows.Forms/tests/IntegrationTests/UIIntegrationTests/ButtonTests.cs:line 93
--- End of stack trace from previous location ---