Merged PR 2429: Bump Microsoft.NET.Test.Sdk from 16.8.3 to 16.9.1

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.8.3 to 16.9.1.

#Release notes

*Sourced from [Microsoft.NET.Test.Sdk's releases](https://github.com/microsoft/vstest/releases).*

> ## v16.9.1
> See the release notes [here](https://github.com/microsoft/vstest-docs/blob/master/docs/releases.md#1691).
>
> ## v16.9.0-preview-20210127-04
> See the release notes [here](https://github.com/microsoft/vstest-docs/blob/master/docs/releases.md#1690-preview-20210127-04).
>
> ## v16.9.0-preview-20210106-01
> See the release notes [here](https://github.com/microsoft/vstest-docs/blob/master/docs/releases.md#1690-preview-20210106-01).
>
> ## v16.9.0-preview-20201123-03
> See the release notes [here](https://github.com/microsoft/vstest-docs/blob/master/docs/releases.md#1690-preview-20201123-03).
>
> -------------------------------
>
> ## v16.9.0-preview-20201020-06
> See the release notes [here](https://github.com/microsoft/vstest-docs/blob/master/docs/releases.md#1690-preview-20201020-06).
>
> -------------------------------
>
> ## 16.9.0-preview-20201020-06
>
> ### Issue Fixed
> * Enable Fakes Datacollector settings to be added in design mode [#2586](microsoft/vstest#2586)
> * Fix blame parameter, warning, and add all testhosts to be ngend [#2579](microsoft/vstest#2579)
> * Add netcoreapp1.0 support to `Microsoft.TestPlatform.TestHost` NuGet [#2569](microsoft/vstest#2569)
> * Use bitness from process or OS [#2571](microsoft/vstest#2571)
> * Restore netcoreapp1.0 support for testhost [#2554](microsoft/vstest#2554)
> * Get symbols of DiaSymReader from externals [#2560](microsoft/vstest#2560)
> * Do not force .NET4.5 in case legacy test settings are provided [#2545](microsoft/vstest#2545)
> * Simplify package references [#2559](microsoft/vstest#2559)
> * Enable default compile items for Microsoft.TestPlatform.PlatformAbstractions [#2556](microsoft/vstest#2556)
> * Avoid logging >Task returned false but did not log an error.< [#2557](microsoft/vstest#2557)
> * Fixed code coverage compatibility issue [#2527](microsoft/vstest#2527)
> * Add environment variables to enable MacOS dump
> * Adding test run attachments processing [#2463](microsoft/vstest#2463)
>
> See full log [here](microsoft/vstest@v16.8.0-release-20200921-02...v16.9.0-preview-20201020-06)
>
> ### Drops
>
> * TestPlatform vsix: [16.9.0-preview-20201020-06](https://vsdrop.corp.microsoft.com/file/v1/Products/DevDiv/microsoft/vstest/master/20201020-06;/TestPlatform.vsix)
> * Microsoft.TestPlatform.ObjectModel : [16.9.0-preview-20201020-06](https://www.nuget.org/packages/Microsoft.TestPlatform.ObjectModel/16.9.0-preview-20201020-06)

...

src/Falu.Tests/Falu.Tests.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
     <PackageReference Include="Moq" Version="4.16.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.analyzers" Version="0.10.0" />