Specifying Python executable path in `nbstripout --install`

[nobodyinperson]

It would be helpful if there was a way to specify the path nbstripout --install puts into e.g. .git/config. This would enable to specify only python or python3, not the full path, which can differ between runtimes, e.g. when using Apptainer/Singularity or Docker containers (/usr/bin/python vs /usr/local/bin/python) occasionally as well as the native Python on the same repo.