[IDP-1146] Add skip-duplicate flag to nuget publish step

Build.ps1

@@ -35,7 +35,7 @@ Process {
 
     # Push to a NuGet feed if the environment variables are set
     if (($null -ne $env:NUGET_SOURCE ) -and ($null -ne $env:NUGET_API_KEY)) {
-      Exec { & dotnet nuget push "$nupkgsPath" -s $env:NUGET_SOURCE -k $env:NUGET_API_KEY }
+      Exec { & dotnet nuget push "$nupkgsPath" -s $env:NUGET_SOURCE -k $env:NUGET_API_KEY --skip-duplicate }
     }
   }
   finally {