Bug#974210: pytorch's autopkg tests fail

[Matthias Klose <doko@debian.org>]

Package: src:pytorch
Version: 1.6.0-5
Severity: serious
Tags: sid bullseye

https://ci.debian.net/packages/p/pytorch

these look all like:

autopkgtest [23:22:49]: test 41_of_47__pytest__test_namedtensor: cd test/ ;
python3 run_test.py -pt -i test_namedtensor -v
autopkgtest [23:22:49]: test 41_of_47__pytest__test_namedtensor:
[-----------------------
Traceback (most recent call last):
  File "run_test.py", line 17, in <module>
    from torch.utils import cpp_extension
  File "/usr/lib/python3/dist-packages/torch/utils/cpp_extension.py", line 8, in
<module>
    import setuptools
ModuleNotFoundError: No module named 'setuptools'



Please also build the package for all supported python3 versions.