Update to MTP

[Youssef1313]

Motivation and Context

Keep the test infra up-to-date with the latest dependencies and moving away from VSTest to the newer Microsoft.Testing.Platform.

How Has This Been Tested?

Manually running tests locally (still not working, that's why it's draft)

Breaking Changes

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Infrastructure and CI

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

[Youssef1313]

@stephentoub This hopefully should be green.

[stephentoub]

Is this issue addressed with MTP?

[Youssef1313]

I'm not 100% sure of the issue you were facing. Worst case if you can still repro, we can add this property back (this property only affects Test Explorer and doesn't affect command-line, so all other work done in this PR can remain).

[Youssef1313]

@stephentoub Do you think what you saw is the same as https://dev.azure.com/devdiv/DevDiv/_workitems/edit/2540441 ?

[stephentoub]

Looks likely

[Youssef1313]

failed ModelContextProtocol.Tests.Transport.StdioClientTransportTests.CreateAsync_ValidProcessInvalidServer_StdErrCallbackInvoked (135ms)
  Assert.InRange() Failure: Value not in range
Range:  (1 - 2147483647)
Actual: 0
  from /home/runner/work/csharp-sdk/csharp-sdk/artifacts/bin/ModelContextProtocol.Tests/Debug/net472/ModelContextProtocol.Tests.exe (Mono 6.8.0.105 (Debian 6.8.0.105+dfsg-3.6ubuntu2 Sun Mar 31 02:55:28 UTC 2024)|x64)
  Assert.InRange() Failure: Value not in range
  Range:  (1 - 2147483647)
  Actual: 0

Is this a flaky test?

[stephentoub]

failed ModelContextProtocol.Tests.Transport.StdioClientTransportTests.CreateAsync_ValidProcessInvalidServer_StdErrCallbackInvoked (135ms)
  Assert.InRange() Failure: Value not in range
Range:  (1 - 2147483647)
Actual: 0
  from /home/runner/work/csharp-sdk/csharp-sdk/artifacts/bin/ModelContextProtocol.Tests/Debug/net472/ModelContextProtocol.Tests.exe (Mono 6.8.0.105 (Debian 6.8.0.105+dfsg-3.6ubuntu2 Sun Mar 31 02:55:28 UTC 2024)|x64)
  Assert.InRange() Failure: Value not in range
  Range:  (1 - 2147483647)
  Actual: 0

Is this a flaky test?

Probably