[pytorch] Disable CUDA sync events by default (#106723)
Summary:
As above, this was missed in a previous diff accidentally setting defaul to true.
Internal to MEta this is disabled but it is enabled in open source PyTorch.
Test Plan: CI
Differential Revision: D48124636
Pull Request resolved: https://github.com/pytorch/pytorch/pull/106723
Approved by: https://github.com/davidberard98, https://github.com/aaronenyeshi
