Bump Microsoft.NET.Test.Sdk from 16.8.3 to 16.9.1 (#186)

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.8.3 to 16.9.1.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v16.8.3...v16.9.1)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

src/common.props

@@ -16,7 +16,7 @@ Should resolve high idle CPU utilization issues detected in earlier versions of
   </PropertyGroup>
   <PropertyGroup>
     <XunitVersion>2.4.1</XunitVersion>
-    <MicrosoftSdkVersion>16.8.3</MicrosoftSdkVersion>
+    <MicrosoftSdkVersion>16.9.1</MicrosoftSdkVersion>
     <FluentAssertionsVersion>5.10.3</FluentAssertionsVersion>
     <NetCoreVersion>netcoreapp3.1</NetCoreVersion>
     <NetStandardVersion>netstandard1.6</NetStandardVersion>