Tests marked with OuterLoop attribute ignore -notrait category=failing

[mkhamoyan]

While running runtime-libraries-mono outerloop tests we noticed that test cases marked with the OuterLoop attribute, which also have attributes like ActiveIssue or SkipOnPlatform, are still being executed and causing failures in the pipeline.

For example, the following test will still run on the browser platform:

[OuterLoop]
[SkipOnPlatform(TestPlatforms.Browser, "Not supported on browser")]

The command passed to Xharness contains:

-trait category=OuterLoop -notrait category=IgnoreForCI -notrait category=failing

This command should work correctly by excluding tests that shouldn't run on specific platforms.

Side Note: If we include the TestPlatforms parameter with the OuterLoop attribute, it respects the platform exclusion, and the tests are skipped as expected. For example:

[OuterLoop("Resource-intensive due to parallel processing", ~TestPlatforms.Browser)]
[SkipOnPlatform(TestPlatforms.Browser, "Not supported on browser")]

[akoeplinger]

This is an xharness-only issue, tracked at dotnet/xharness#908

[mkhamoyan]

Thanks, I'll close this one.