Remove C++17 only optional include (#56782)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56782
Fixes #56749
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: H-Huang
Differential Revision: D28000019
Pulled By: ezyang
fbshipit-source-id: 87f86a402dac87e6c101aef8c78a928ce7d21340
