Use CFS feed instead of public npm when generate emitter-package-lock.json

[msyyc]

Context: https://teams.microsoft.com/l/message/19:b97d98e6d22c41e0970a1150b484d935@thread.skype/1787548200842?tenantId=72f988bf-86f1-41af-91ab-2d7cd011db47&groupId=3e17dcb0-4257-4a30-b843-77f47f1d4121&parentMessageId=1787223971320&teamName=Azure%20SDK&channelName=Language%20-%20Python&createdTime=1787548200842

When generate emitter-package-lock.json, we should use CFS feed instead of public npm to avoid pin latest npm package which is unavailable in CFS which may block SDK generation in users' local machine.