[BUG] 61.0.0 breaks "setup.py install" by missing dependencies in install_requires

### setuptools version



61.0.0



### Python version



3.10



### OS



ubuntu-latest in GitHub Actions



### Additional environment information



_No response_



### Description



In our pywbem package, we test the different documented methods to install the package. One of them is still "setup.py install". I do understand that it is deprecated since setuptools v58.3.0, but that still means it should be expected to work.



The issue is that the "setup.py install" command successfully installs the pywbem package, but upon import it turns out that dependent packages were not installed, e.g. "six".



The GitHub Actions test run showing that is: https://github.com/pywbem/pywbem/runs/5687824533?check_suite_focus=true



"pip install" on the package works with setuptools 61.0.0 and does install the dependent packages.



The requirements.txt file of the pywbem project does specify the dependent packages and the setup.py script loads the dependencies from requirements.txt and specifies them in the "install_requires" parameter of setup().



The "setup.py install" approach worked before setuptools 61.0.0, e.g. with 60.10.0, see [this test run](https://github.com/pywbem/pywbem/runs/5626093559?check_suite_focus=true#step:22:2157).



### Expected behavior



61.0.0 should still support "setup.py install" as before.



### How to Reproduce



1. Create a new virtual env on Python 3.10

2. `pip install setuptools==61.0.0; pip uninstall six`

3. `git clone https://github.com/pywbem/pywbem.git; cd pywbem`

4. `./setup.py install`  # should succeed

5. `pip list`  # should display:

   ```

   Package    Version

   ---------- ----------

   pip        22.0.4

   pywbem     1.5.0.dev1

   setuptools 61.0.0

   wheel      0.37.1

   ```

   and the issue is that the dependent packages are not installed.

6. `pip install .`  # should succeed

7. `pip list`  # should display the correctly installed dependencies:

   ```

   Package            Version

   ------------------ ----------

   certifi            2021.10.8

   charset-normalizer 2.0.12

   idna               3.3

   nocasedict         1.0.2

   nocaselist         1.0.4

   pip                22.0.4

   ply                3.11

   pywbem             1.5.0.dev1

   PyYAML             6.0

   requests           2.27.1

   setuptools         61.0.0

   six                1.16.0

   urllib3            1.26.9

   wheel              0.37.1

   yamlloader         1.1.0

   ```



### Output



See above

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