- In the Cygwin CI workflow, move `runs-on` below `strategy`, for  greater consistency with other workflows.- In the Cygwin CI jobs, use `pwsh` rather than `bash` for the  `git config` command run outside of Cygwin, since `pwsh` is the  default shell for such commands, it's the shell the Cygwin setup  action uses, and it avoids creating the wrong impression that  `bash` is needed.- Use "virtual environment" instead of "virtualenv" in some step  names to avoid possible confusion with the `virtualenv` pacakge.- Remove comments in the PyPA package upgrade steps, which are  more self-documenting since727f4e9 (gitpython-developers#2043).

This installs the `python-pip-wheel`, `python-setuptools-wheel`,and `python-wheel-wheel` packages on Cygwini CI, which provide`.whl` files for `pip`, `setuptools`, and `wheel`.By making those wheels available, thisfixesgitpython-developers#2004 better than theprevious workaround, allowing `ensurepip` to run without the error:    Traceback (most recent call last):      File "/usr/lib/python3.9/runpy.py", line 188, in _run_module_as_main        mod_name, mod_spec, code = _get_module_details(mod_name, _Error)      File "/usr/lib/python3.9/runpy.py", line 147, in _get_module_details        return _get_module_details(pkg_main_name, error)      File "/usr/lib/python3.9/runpy.py", line 111, in _get_module_details        __import__(pkg_name)      File "/usr/lib/python3.9/ensurepip/__init__.py", line [30](https://github.com/EliahKagan/GitPython/actions/runs/13454947366/job/37596811693#step:10:31), in <module>        _SETUPTOOLS_VERSION = _get_most_recent_wheel_version("setuptools")      File "/usr/lib/python3.9/ensurepip/__init__.py", line 27, in _get_most_recent_wheel_version        return str(max(_wheels[pkg], key=distutils.version.LooseVersion))    ValueError: max() arg is an empty sequenceThis change takes the place of the main changes ingitpython-developers#2007 andgitpython-developers#2009.In particular, it should allow `test_installation` to pass again.This also delists non-wheel Cygwin packages such as `python39-pip`,which are not needed (or at least no longer needed).(The python-{pip,setuptools,wheel}-wheel packages are, as theirnames suggest, intentionally not specific to Python 3.9. However,this technique will not necessarily carry over to Python 3.12,depending on what versions are supplied and other factors. This maybe relevant when another attempt likegitpython-developers#1988 is made to test/supportPython 3.12 on Cygwin. At least for now, though, this seemsworthwhile for fixing the Cygwin 3.9 environment, making it moresimilar to working local Cygwin environments and letting theworkflow be more usable as guidance to how to set up a local Cygwinenvironment for GitPython development, and letting the installationtest pass automatically.)