Update Nuget Commandline package

This commit updates the Nuget command line package to a version that
supports the <icon> element in nuspec files.

(cherry picked from commit aca0c58)

Author: russcam

build/scripts/scripts.fsproj

@@ -37,7 +37,7 @@
     <PackageReference Include="ILRepack" Version="2.1.0-beta1" />
     <PackageReference Include="FSharp.Core" Version="4.6.2" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.1" />
-    <PackageReference Include="NuGet.CommandLine" Version="4.9.4" />
+    <PackageReference Include="NuGet.CommandLine" Version="5.3.1" />
     <PackageReference Include="Octokit" Version="0.32.0" />
     <PackageReference Include="Proc" Version="0.6.1" />
   </ItemGroup>