Update xUnit to latest v3 and resolve build issues

[Copilot]

This PR updates xUnit from v2.9.3 to v3.2.0-pre.10 and resolves all associated build errors and warnings.

Changes Made

• xUnit Package: Updated from xunit v2.9.3 to xunit.v3 v3.2.0-pre.10
• ValueTask Return Types: Updated all IAsyncLifetime implementations (23 test files) to return ValueTask instead of Task for InitializeAsync() and DisposeAsync() methods, as required by xUnit v3
• Cancellation Token Support: Added TestContext.Current.CancellationToken to 120+ async method calls across 24 test files to enable responsive test cancellation
• Using Statements: Added using Xunit.v3; where needed to access TestContext

Testing

• ✅ Build succeeds with 0 errors and 0 warnings
• ✅ Compatible with both .NET 8.0 and .NET 9.0 target frameworks
• ✅ All xUnit v3 analyzer warnings resolved

Note: MongoDB is required to run the actual tests, but the code compiles successfully without it.

Fixes #4

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Update xUnit to latest v3</issue_title>
<issue_description>Need to update xUnit to v3.

• Fix all warnings about cancellation tokens
• Fix all build errors looking for ValueTask rather than Task</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Update xUnit to latest v3 #4

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[JohnCampionJr]

@copilot your environment will require mongodb installed to successfully run the tests

[Copilot]

@copilot your environment will require mongodb installed to successfully run the tests

Understood. MongoDB is not available in this environment, so I'll update xUnit and fix any build errors/warnings, but won't be able to run the full test suite. I'll ensure the code compiles successfully.