Bump Microsoft.NET.Test.Sdk in /samples/snippets/csharp/xunit-test (#29398)

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 17.1.0 to 17.2.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v17.1.0...v17.2.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

samples/snippets/csharp/xunit-test/xunit-test.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5" />
   </ItemGroup>