Update nuget.config

NuGet.config

@@ -4,11 +4,6 @@
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
     <add key="darc-pub-dotnet-corefx-8a3ffed" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-corefx-8a3ffed5/nuget/v3/index.json" />
-    <add key="darc-int-dotnet-extensions-be18161" value="https://pkgs.dev.azure.com/dnceng/_packaging/darc-int-dotnet-extensions-be18161f/nuget/v3/index.json" />
-    <add key="darc-int-dotnet-efcore-509fe04" value="https://pkgs.dev.azure.com/dnceng/_packaging/darc-int-dotnet-efcore-509fe041/nuget/v3/index.json" />
-    <add key="darc-int-dotnet-core-setup-3acd9b0" value="https://pkgs.dev.azure.com/dnceng/_packaging/darc-int-dotnet-core-setup-3acd9b0c/nuget/v3/index.json" />
-    <add key="darc-int-dotnet-corefx-059a4a1" value="https://pkgs.dev.azure.com/dnceng/_packaging/darc-int-dotnet-corefx-059a4a19/nuget/v3/index.json" />
-    <add key="darc-int-dotnet-aspnetcore-tooling-d63ec4a" value="https://pkgs.dev.azure.com/dnceng/_packaging/darc-int-dotnet-aspnetcore-tooling-d63ec4a1/nuget/v3/index.json" />
     <!--End: Package sources managed by Dependency Flow automation. Do not edit the sources above.-->
     <add key="dotnet-core" value="https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json" />
     <add key="dotnet-eng" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" />