Convert Maui27202 and Maui28711 tests from NUnit to XUnit

[PureWeen]

No description provided.

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.sh | bash -s -- 33061

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/maui/main/eng/scripts/get-maui-pr.ps1) } 33061"

[PureWeen]

/backport release/10.0.1xx-sr2

[Copilot]

Pull request overview

This PR converts two XAML unit test files from NUnit to XUnit, aligning them with the current testing framework standard used throughout the Controls.Xaml.UnitTests project.

Key Changes

• Converted test framework attributes from NUnit to XUnit syntax ([TestFixture] → [Collection("Issue")], [Test] → [Theory], [Values] → [XamlInflatorData])
• Replaced NUnit-style assertions with XUnit equivalents (Assert.That() → Assert.Equal()/Assert.NotNull()/Assert.True())
• Updated lifecycle methods from NUnit to XUnit patterns ([SetUp]/[TearDown] → Constructor/IDisposable)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Controls/tests/Xaml.UnitTests/Issues/Maui28711.xaml.cs	Converted test for verifying x:Name on SolidColorBrush resources; changed from NUnit to XUnit with proper assertion syntax
src/Controls/tests/Xaml.UnitTests/Issues/Maui27202.xaml.cs	Converted test for derived styles inheriting VisualStateManager; migrated setup/teardown to constructor/IDisposable pattern and updated assertions to XUnit

[PureWeen]

/backport to release/10.0.1xx-sr2

[github-actions]

Started backporting to release/10.0.1xx-sr2 (link to workflow run)

[PureWeen]

• merging to fix main