Update to xunit v3

[martincostello]

• Update to xunit v3.
• Avoid infinite loop and throw if test times out.

Resolves #2439.

[Copilot]

Copilot reviewed 143 out of 158 changed files in this pull request and generated no comments.

Files not reviewed (15)

• Directory.Packages.props: Language not supported
• eng/Test.targets: Language not supported
• src/Snippets/Snippets.csproj: Language not supported
• test/Polly.Core.Tests/CircuitBreaker/Controller/CircuitStateControllerTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/BrokenCircuitExceptionTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/IsolatedCircuitExceptionTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/Fallback/FallbackHandlerTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/CircuitBreakerResiliencePipelineBuilderTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/CircuitBreakerOptionsTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/CircuitBreakerResilienceStrategyTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/Fallback/FallbackResiliencePipelineBuilderExtensionsTests.cs: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/CircuitBreakerStateProviderTests.cs: Evaluated as low risk
• src/Snippets/Docs/Testing.cs: Evaluated as low risk
• build.cake: Evaluated as low risk
• test/Polly.Core.Tests/CircuitBreaker/CircuitBreakerPredicateArgumentsTests.cs: Evaluated as low risk

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.39%. Comparing base (f982bb6) to head (43001fd).
Report is 120 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2440   +/-   ##
=======================================
  Coverage   85.39%   85.39%           
=======================================
  Files         312      312           
  Lines        7464     7464           
  Branches     1121     1121           
=======================================
  Hits         6374     6374           
  Misses        905      905           
  Partials      185      185           

Flag	Coverage Δ
linux	85.39% <ø> (ø)
macos	85.39% <ø> (ø)
windows	85.33% <ø> (-0.03%)	⬇️

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[github-actions]

This pull request is stale because it has been open for 60 days with no activity. It will be automatically closed in 14 days if no further changes are made.