aspell-python-py3 → pyspelling / textutils3

Because of pending PRs and lack of release since 2016, should we switch from [aspell-python-py3](https://github.com/WojciechMula/aspell-python/) to [PySpelling](https://github.com/facelessuser/pyspelling) or [textutils3](https://pypi.org/project/textutils3/)?