The .NET SDK is unnecessarily shipping 'ref' assemblies in the product

[eerhardt]

We are shipping "ref" assemblies of our product assemblies inside the .NET SDK. These files are not necessary. We should remove them.

C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57❯ foreach ($dir in gci -re -in "ref" ) { gci $dir.FullName | select FullName }

FullName
--------
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\DotnetTools\dotnet-watch\6.0.100-rc.2.21505.11\tools\net6.0\any\ref\dotnet-watch.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Microsoft\Microsoft.NET.Build.Extensions\tools\net6.0\ref\Microsoft.NET.Build.Extensions.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\ref\MSBuild.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\ref\mscorlib.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\ref\netstandard.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk\tools\net6.0\ref\Microsoft.NET.Build.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.BlazorWebAssembly\tools\net6.0\ref\Microsoft.NET.Sdk.BlazorWebAssembly.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.Publish\tools\net6.0\ref\Microsoft.NET.Sdk.Publish.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.Razor\tasks\net6.0\ref\Microsoft.NET.Sdk.Razor.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.Web\tools\net6.0\ref\Microsoft.NET.Sdk.Web.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.Web.ProjectSystem\tools\net6.0\ref\Microsoft.NET.Sdk.Web.ProjectSystem.Tasks.dll
C:\Program Files\dotnet\sdk\6.0.100-rc.2.21505.57\Sdks\Microsoft.NET.Sdk.Worker\tools\net6.0\ref\Microsoft.NET.Sdk.Worker.Tasks.dll

AFAICT - this is due to the fact that $(ProduceReferenceAssembly) is true during our build, and whatever mechanism we are using to deploy the above projects is picking up the reference assembiles.

See the discussion here: dagood/source-build#9 (comment)

cc @sfoslund @dsplaisted