Don't override the toolset compiler for runtime tests

Author: tannergooding

src/tests/Directory.Build.props

@@ -8,12 +8,6 @@
   <Import Project="$(MSBuildThisFileDirectory)\Common\dir.sdkbuild.props" Condition="'$(UsingMicrosoftNETSdk)' == 'true'"  />
   <Import Project="$(MSBuildThisFileDirectory)\Common\dir.common.props" Condition="'$(UsingMicrosoftNETSdk)' != 'true'"  />
 
-  <PropertyGroup>
-    <!-- Override the compiler version with a private build that supports runtime-async -->
-    <MicrosoftNetCompilersToolsetVersion>5.0.0-1.25259.6</MicrosoftNetCompilersToolsetVersion>
-    <RoslynCompilerType>Custom</RoslynCompilerType>
-  </PropertyGroup>
-
   <PropertyGroup>
     <RunningOnUnix Condition="('$(RunningOnUnix)' == '') And ('$(MSBuildRuntimeType)' == 'Core') And ('$(OS)'!='Windows_NT')">true</RunningOnUnix>
   </PropertyGroup>

src/tests/async/Directory.Build.props

@@ -9,6 +9,7 @@
     <EnableNETAnalyzers>false</EnableNETAnalyzers>
     <Features>$(Features);runtime-async=on</Features>
   </PropertyGroup>
+
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)RuntimeAsyncMethodGenerationAttribute.cs" />
   </ItemGroup>