Prevent prebuilts from ending up in the sharedframework

--- a/src/pkg/packaging-tools/framework.sharedfx.props

+++ b/src/pkg/packaging-tools/framework.sharedfx.props

@@ -26,8 +26,6 @@

     <RestoreAllBuildRids>false</RestoreAllBuildRids>

     <RestoreConfigFile>$(ProjectDir)NuGet.config</RestoreConfigFile>

-    

-    <RestoreFallbackFolders>$(PackagesDir)</RestoreFallbackFolders>

     <EnsureRuntimePackageDependencies>false</EnsureRuntimePackageDependencies>