use better secrets for upload labels workflow (#68013)
Summary:
Should prevent https://github.com/pytorch/pytorch/runs/4134946329?check_suite_focus=true
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68013
Reviewed By: seemethere
Differential Revision: D32254046
Pulled By: janeyx99
fbshipit-source-id: 55a7a1b8f8434f6608fe9d423982406c1e187c59
