[BE] Get rid of `future` (#92596)
PyTorch has been Python-3.X+ for ages, so it's a shame to still rely on `future.utils` even in a deprecated Caffe2 codebase
For the reference:
https://peps.python.org/pep-0469/#migrating-directly-to-python-3
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92596
Approved by: https://github.com/kit1980, https://github.com/orionr
