Remove private _download_url_to_file (#74429)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/74429
Test Plan: Imported from OSS
Reviewed By: anjali411
Differential Revision: D35011899
Pulled By: NicolasHug
fbshipit-source-id: 92468c2eff1b37d1676bc97ed4966fba6c3dc10c
(cherry picked from commit 44937c722058b3341ceca1906a4d4113f08a2755)
