Remove auditSources from NuGet.config (#11184)

The api.nuget.org source will clash with the CFSClean network isolation policy

Author: akoeplinger

NuGet.config

@@ -18,9 +18,5 @@
     <add key="dotnet11" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet11/nuget/v3/index.json" />
     <add key="dotnet11-transport" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet11-transport/nuget/v3/index.json" />
   </packageSources>
-  <auditSources>
-    <clear />
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-  </auditSources>
   <disabledPackageSources />
 </configuration>