building torchao in a fresh conda env does not work

[vkuzo]

1. create a fresh conda env with PyTorch 2.9 and Python 3.12
2. try to build torchao from source, it will fail:

(pytorch_29) [vasiliy@devgpu023.atn1 ~/local/ao (main)]$ with-proxy USE_CPP=1 python setup.py develop
...
  error: subprocess-exited-with-error                                                                                                                                                                                10:42:23 [114/444]
                                                                                                                                                                                                                                       
  × Getting requirements to build editable did not run successfully.                                                                                                                                                                   
  │ exit code: 1                                                                                                                                                                                                                       
  ╰─> [23 lines of output]                                                                                                                                                                                                             
      Traceback (most recent call last):                                                                                                                                                                                               
        File "/home/vasiliy/.conda/envs/pytorch_29/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 389, in <module>                                                                         
          main()                                                                                                                                                                                                                       
        File "/home/vasiliy/.conda/envs/pytorch_29/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 373, in main                                                                                       json_out["return_val"] = hook(**hook_input["kwargs"])       
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^                         
        File "/home/vasiliy/.conda/envs/pytorch_29/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 157, in get_requires_for_build_editable
          return hook(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-r5_f40fl/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 473, in get_requires_for_build_editable
          return self.get_requires_for_build_wheel(config_settings)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-r5_f40fl/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 331, in get_requires_for_build_wheel
          return self._get_build_requires(config_settings, requirements=[])
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        File "/tmp/pip-build-env-r5_f40fl/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 301, in _get_build_requires
          self.run_setup()
        File "/tmp/pip-build-env-r5_f40fl/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 512, in run_setup
          super().run_setup(setup_script=setup_script)
        File "/tmp/pip-build-env-r5_f40fl/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 317, in run_setup                              
          exec(code, locals())
        File "<string>", line 101, in <module>
      ModuleNotFoundError: No module named 'torch'
      [end of output]

The user can manually work around by doing

pip install setuptools==78.1.1

We should make sure we require the right setuptools version automatically without requiring the manual workaround, this is a footgun