nuget-azure-ad-b2c-backend: bump Microsoft.NET.Test.Sdk (#2048)

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 17.11.1 to 17.12.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](microsoft/vstest@v17.11.1...v17.12.0)

---
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>

samples/AzureADB2CAuth/auth-backend/Directory.Packages.props

@@ -7,7 +7,7 @@
     <PackageVersion Include="Microsoft.Extensions.Logging" Version="8.0.0" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.1" />
     <PackageVersion Include="Microsoft.Identity.Web" Version="3.2.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageVersion Include="NSwag.AspNetCore" Version="14.1.0" />
     <PackageVersion Include="NSwag.MSBuild" Version="14.1.0" />
     <PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" />