Properly import LooseVersion (#69904)
Summary:
This fixes regression introduced by https://github.com/pytorch/pytorch/pull/57040
Somehow importing `distutils` from `setuptool` caused import of
`distutils.versions`, which is not a documented dependency and got
change with the release of
[setuptools-59.6.0](https://github.com/pypa/setuptools/tree/v59.6.0)
We should not rely on that, as
`import distutils` never re-imports `distutils.version`, which one can
see by observing
https://github.com/python/cpython/blob/3.9/Lib/distutils/__init__.py
or by running:
```
% python3 -c "import distutils;print(distutils.__version__, dir(distutils))"
3.7.5 ['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', 'sys']
% python3 -c "from setuptools import distutils;print(distutils.__version__, dir(distutils))"
3.7.5 ['__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__path__', '__spec__', '__version__', 'archive_util', 'ccompiler', 'cmd', 'config', 'core', 'debug', 'dep_util', 'dir_util', 'dist', 'errors', 'extension', 'fancy_getopt', 'file_util', 'filelist', 'log', 'spawn', 'sys', 'sysconfig', 'util', 'version']
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69904
Reviewed By: albanD, atalman, janeyx99
Differential Revision: D33094453
Pulled By: malfet
fbshipit-source-id: aaf1adb7c6f293c4e376ccff21c64cd6ba625e97
