Disable DispatcherQueueHelper_Action_Null to patch random WinUI 3 test failures

[Arlodotexe]

This PR follow up to the investigation enabled by #493 and aims to workaround the random WinUI 3 crash documented in #347 by disabling the offending test.

Since the random test failures took ~5 tries to get a successful failure and crash dump in #493, this PR will need to see at minimum 10 (max ~15) successful reruns before we can say we have confidence that it fixes the issue.

[michael-hawker]

Did we not want to do this on the crash #493 PR so if there's another failure we can get another dump?

[Arlodotexe]

Did we not want to do this on the crash #493 PR so if there's another failure we can get another dump?

Good point. Given the stack trace we saw, I had enough confidence that this might fix it that I didn't plan for it to fail, focusing instead on separating concerns.

I have a small script running locally to monitor the CI for this PR and rerun until completion, or to notify me on failure.

If a failure is caught, we still have the option to close off #493 and bring those changes into here.

[Arlodotexe]

Ah, looks like this didn't do it:

  Passed SimpleSynchronousExampleTest [< 1 ms]
The active test run was aborted. Reason: Unable to communicate with test host process.
Terminating app with process ID '3628'.
Results File: D:\a\Windows\Windows\TestResults\wasdk.trx


Test Run Aborted.
Total tests: Unknown
     Passed: 345
    Skipped: 3
 Total time: 35.9914 Seconds
Error: Process completed with exit code 1.

#493 should close into main soon, let's get that pulled into here so we can get those crash dumps.

[michael-hawker]

Now ColorPickerTests.ExampleColorPickerTestClass.ComplexAsyncUIExampleTest, crash dumps collected it looks like

Most of these are just the dummy tests we have as placeholders for basic construction of the control. It's like something within the structure of the tests themselves.

[Arlodotexe]

Looks like it's happening in DispatcherQueueHelper_FuncOfT_Null now, same issue as before:

Fix is to disable all tests that pass a suppressed null action

[Arlodotexe]

Now the error has changed to this, which is... new.

This is suggesting that the crash happens because AutoSuggestBox_TextChanged is being raised and the body of that handler is trying to access a subproperty on the Owner DP (of type TokenizingTextBoxItem, derives ListViewItem) through here, but that item is disposed.

It doesn't tell us which test is dying anymore, either. Hmm.