Bump Microsoft.NET.Test.Sdk from 16.8.3 to 16.9.1 (#534)

Author: dependabot[bot]

Directory.Build.targets

@@ -25,7 +25,7 @@
     <PackageReference Update="Microsoft.Extensions.Options.ConfigurationExtensions" Version="2.0.0" />
     <PackageReference Update="Microsoft.Extensions.DependencyInjection" Version="2.0.0" />
     <PackageReference Update="Newtonsoft.Json" Version="11.0.2" />
-    <PackageReference Update="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+    <PackageReference Update="Microsoft.NET.Test.Sdk" Version="16.9.1" />
     <PackageReference Update="xunit.runner.visualstudio" Version="2.4.3" />
     <PackageReference Update="xunit" Version="2.4.1" />
     <PackageReference Update="FluentAssertions" Version="5.10.3" />