Bump Microsoft.NET.Test.Sdk from 16.11.0 to 17.8.0 in /lang/csharp

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.11.0 to 17.8.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](microsoft/vstest@v16.11.0...v17.8.0)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

lang/csharp/versions.props

@@ -55,7 +55,7 @@
     <MicrosoftBuildFrameworkVersion>16.8.0</MicrosoftBuildFrameworkVersion>
     <MicrosoftBuildUtilitiesCoreVersion>16.8.0</MicrosoftBuildUtilitiesCoreVersion>
     <MicrosoftCodeAnalysisNetAnalyzersVersion>5.0.3</MicrosoftCodeAnalysisNetAnalyzersVersion>
-    <MicrosoftNETTestSdkVersion>16.11.0</MicrosoftNETTestSdkVersion>
+    <MicrosoftNETTestSdkVersion>17.8.0</MicrosoftNETTestSdkVersion>
     <NUnitVersion>3.13.2</NUnitVersion>
     <NUnitConsoleRunnerVersion>3.12.0</NUnitConsoleRunnerVersion>
     <NUnit3TestAdapterVersion>3.17.0</NUnit3TestAdapterVersion>