remove redundant getDispatchKeySetUnboxed(eligibleKeys) (#58535)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/58535
Test Plan: Imported from OSS
Reviewed By: bdhirsh
Differential Revision: D28531377
Pulled By: bhosmer
fbshipit-source-id: ade1427c8c9ada10ecdc69ef80c5d90be23f5787
