Updated CONTRIBUTING.md (#72044)
Summary:
Removed duplicate statements
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72044
Reviewed By: albanD
Differential Revision: D33883764
Pulled By: mrshenli
fbshipit-source-id: db467b2adec6a62edf132a70f70e665a97266fa4
(cherry picked from commit aa38c8af79eea946cfb66ad6e3eff578363c48a4)
