Remove duplicate references to FSharp.Core (#416)

src/FSharpWrapper/FSharpWrapper.fsproj

@@ -8,7 +8,6 @@
     <DocumentationFile>bin\$(Configuration)\$(TargetFramework)\Microsoft.ML.Probabilistic.FSharp.XML</DocumentationFile>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="FSharp.Core" Version="4.7.2" />
     <PackageReference Update="System.ValueTuple" Version="4.5.0" />
   </ItemGroup>
   <ItemGroup>

test/TestFSharp/TestFSharp.fsproj

@@ -52,7 +52,6 @@
     <ProjectReference Include="..\..\src\FSharpWrapper\FSharpWrapper.fsproj" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="FSharp.Core" Version="4.7.2" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.6.1" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.2">