Optim foreach cleanup for RAdam (#70230)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/70230
Test Plan: Imported from OSS
Reviewed By: anjali411
Differential Revision: D33767874
Pulled By: mikaylagawarecki
fbshipit-source-id: 9379db24266a7bbcc2c23849f87ae0af2e6729c0
(cherry picked from commit ecf7b31fc39ccfeeef36bb763ca8c96960be3577)
