Remove pybind11 from required submodules (#44278)
Summary:
This can be taken from the system in which case it is not used from the submodule. Hence the check here limits the usage unnecessarily
ccing malfet
Pull Request resolved: https://github.com/pytorch/pytorch/pull/44278
Reviewed By: malfet
Differential Revision: D23568552
Pulled By: ezyang
fbshipit-source-id: 7fd2613251567f649b12eca0b1fe7663db9cb58d
