The latest pip documentation recommends using `pip wheel` command to make the
wheel; see <https://pip.pypa.io/en/stable/cli/pip_wheel/#pip-wheel>.

This has also the advantage that the Python packages `build` and `setuptools`
are no longer required to build the wheel.

The new command is
```
python3 -m pip wheel <build-dir> --no-deps --wheel <output-dir>
```