[XNNPACK] Enable Memopt for OSS (#93097)
Summary:
D38543798
Enabled Memopt previously to fix a bug with memory planner
Mirroring the changes we made Internally to OSS
Test Plan: OSS CI
Reviewed By: digantdesai
Differential Revision: D42782958
Pull Request resolved: https://github.com/pytorch/pytorch/pull/93097
Approved by: https://github.com/digantdesai
