Downgrade test runner

Author: dnperfors

test/Directory.Build.targets

@@ -2,7 +2,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="3.0.1">
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>