Bump Microsoft.NET.Test.Sdk from 16.9.1 to 16.9.4

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.9.1 to 16.9.4.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v16.9.1...v16.9.4)

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

Author: dependabot-preview[bot]

XmlSchemaClassGenerator.Tests/XmlSchemaClassGenerator.Tests.csproj

@@ -25,7 +25,7 @@
     </PackageReference>
     <PackageReference Include="Glob.cs" Version="5.0.224" />
     <PackageReference Include="Microsoft.Net.Compilers.netcore" Version="1.3.2" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.4" />
     <PackageReference Include="System.CodeDom" Version="5.0.0" />
     <PackageReference Include="System.Text.Encoding.CodePages" Version="5.0.0" />
     <PackageReference Include="System.ValueTuple" Version="4.5.0" />