[mobile] Add MacCatalyst to Console OpenStandardHandle test exclusions

[github-actions]

Fixes System.Console.Tests failures on MacCatalyst discovered in runtime-extra-platforms build #1388505.

Failure

Build: #1388505 (2026-04-21)
Job: maccatalyst-arm64 Release AllSubsets_Mono
Helix job: f4caa84e-1526-4c12-a872-6f24ac6f3ba1
Work item: System.Console.Tests
Platform: MacCatalyst arm64 (also affects maccatalyst-x64)

Failed tests

Four tests failed with PlatformNotSupportedException:

1. OpenStandardInputHandle_ReturnsValidHandle
2. OpenStandardOutputHandle_ReturnsValidHandle
3. OpenStandardErrorHandle_ReturnsValidHandle
4. OpenStandardHandles_DoNotOwnHandle

[FAIL] System.Tests.ConsoleTests.OpenStandardInputHandle_ReturnsValidHandle
System.PlatformNotSupportedException : Operation is not supported on this platform.
   at System.ConsolePal.OpenStandardInputHandle()
   at System.Console.OpenStandardInputHandle()

Root cause

The Console.OpenStandardXXXHandle() methods throw PlatformNotSupportedException on mobile platforms (iOS, tvOS, Android, MacCatalyst) because these platforms do not expose the underlying file handles for standard streams.

The existing tests already had [PlatformSpecific] attributes excluding iOS, tvOS, and Android, but MacCatalyst was missing from the exclusion list. This is an oversight because MacCatalyst has the same limitation as other Apple mobile platforms.

Fix

Add TestPlatforms.MacCatalyst to the exclusion list (using & ~TestPlatforms.MacCatalyst) on all five tests that attempt to use these APIs, and add it to the inclusion list on the three "ThrowsOnUnsupportedPlatforms" tests that validate the exception is thrown.

This makes the skip coverage consistent across all mobile platforms:

• Skip on: iOS, tvOS, MacCatalyst, Android, Browser (where applicable)
• Run on: Windows, Linux, macOS desktop

Testing

After this fix, the four failing tests will be skipped on MacCatalyst in the runtime-extra-platforms pipeline, matching the behavior on iOS, tvOS, and Android.

---

Note

This PR was created by GitHub Copilot after analyzing mobile platform CI failures in the runtime-extra-platforms pipeline (build 1388505).

Note

🔒 Integrity filter blocked 1 item

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• #126805 search_pull_requests: has lower integrity than agent requires. The agent cannot read data with integrity below "approved".

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Generated by Mobile Platform Failure Scanner · ● 2.2M · ◷

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[Copilot]

Pull request overview

This PR fixes System.Console.Tests failures on MacCatalyst by aligning the PlatformSpecific test filters with other mobile platforms where Console.OpenStandard*Handle() is not supported.

Changes:

• Exclude TestPlatforms.MacCatalyst from tests that expect standard handles to be available/usable.
• Include TestPlatforms.MacCatalyst in tests that validate PlatformNotSupportedException is thrown on unsupported platforms.

[adamsitnik]

LGTM, we need to update the code review skill to require the tests to be annotated when testing APIs that are not available on every platform