Remove nuget.org

Author: safesparrow

NuGet.config

@@ -13,7 +13,6 @@
     <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
     <add key="vssdk" value="https://pkgs.dev.azure.com/azure-public/vside/_packaging/vssdk/nuget/v3/index.json" />
     <add key="vs-impl" value="https://pkgs.dev.azure.com/azure-public/vside/_packaging/vs-impl/nuget/v3/index.json" />
-    <add key="Nuget.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
   <disabledPackageSources>
     <clear />