build(deps): bump Microsoft.NET.Test.Sdk from 16.7.1 to 16.8.0

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.7.1 to 16.8.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v16.7.1...v16.8.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

src/Directory.build.props

@@ -36,7 +36,7 @@
   </PropertyGroup>
 
   <ItemGroup Condition="$(IsTestProject) or $(MSBuildProjectName.Contains('TestRunner'))">
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="Xunit.StaFact" Version="1.0.37" />
     <PackageReference Include="FluentAssertions" Version="5.10.3" />