fix: comment out react-native package source

Author: vineethkuttan

samples/Calculator/fabric/NuGet.config

@@ -2,7 +2,7 @@
 <configuration>
   <packageSources>
     <clear />
-    <add key="react-native" value="https://pkgs.dev.azure.com/ms/react-native/_packaging/react-native-public/nuget/v3/index.json" />
+    <!-- <add key="react-native" value="https://pkgs.dev.azure.com/ms/react-native/_packaging/react-native-public/nuget/v3/index.json" /> -->
     <add key="Nuget.org" value="https://api.nuget.org/v3/index.json" />
   </packageSources>
   <disabledPackageSources>