Bump NUnit from 3.13.2 to 4.2.2 in /lang/csharp

Bumps [NUnit](https://github.com/nunit/nunit) from 3.13.2 to 4.2.2.
- [Release notes](https://github.com/nunit/nunit/releases)
- [Changelog](https://github.com/nunit/nunit/blob/main/CHANGES.md)
- [Commits](nunit/nunit@v3.13.2...4.2.2)

---
updated-dependencies:
- dependency-name: NUnit
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

lang/csharp/versions.props

@@ -56,7 +56,7 @@
     <MicrosoftBuildUtilitiesCoreVersion>16.8.0</MicrosoftBuildUtilitiesCoreVersion>
     <MicrosoftCodeAnalysisNetAnalyzersVersion>5.0.3</MicrosoftCodeAnalysisNetAnalyzersVersion>
     <MicrosoftNETTestSdkVersion>16.11.0</MicrosoftNETTestSdkVersion>
-    <NUnitVersion>3.13.2</NUnitVersion>
+    <NUnitVersion>4.2.2</NUnitVersion>
     <NUnitConsoleRunnerVersion>3.12.0</NUnitConsoleRunnerVersion>
     <NUnit3TestAdapterVersion>3.17.0</NUnit3TestAdapterVersion>
     <StyleCopAnalyzersVersion>1.1.118</StyleCopAnalyzersVersion>