Change registration page javascript extending source from ce to ee

What does this MR do and why?

We added ee/app/assets/javascripts/pages/registrations/new/index.js in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/85765/diffs#762f33744e401def691782d50ca37f7af00d97d9, now jh/app/assets/javascripts/pages/registrations/new/index.js should extend ee/app/assets/javascripts/pages/registrations/new/index.js rather than ce/app/assets/javascripts/pages/registrations/new/index.js

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