F# now supports reference assemblies

Generation of reference assemblies for F# was disabled previously (dotnet#13085) because the F# compiler didn't support them.
Now both, the F# compiler (dotnet/fsharp#12334) and the FCS task (dotnet/fsharp#13263) support reference assemblies. Also, the bug around the copying of F# ref assemblies was fixed (dotnet/fsharp#13266) so it is time to enable the generation of ref assemblies for F#.s

src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.FSharp.props

@@ -28,8 +28,4 @@ Copyright (c) .NET Foundation. All rights reserved.
   </PropertyGroup>
   <Import Condition=" '$(UseBundledFSharpTargets)' == 'true' and Exists('$(FSharpPropsShim)') " Project="$(FSharpPropsShim)" />
 
-  <PropertyGroup>
-    <ProduceReferenceAssembly>false</ProduceReferenceAssembly>
-  </PropertyGroup>
-
 </Project>