Add support for Python 3.9 and 3.10

[Kenshiro-28]

Issue summary

Gym Retro is a great project that allows to use classic games from consoles like Sega Genesis or SNES for machine learning. Currently it only supports Python 3.8 which is a problem because even conservative distros like Debian stable are already using Python 3.9.

Please add support for Python 3.9 (current Debian stable) and Python 3.10 (next stable)

[victorsevero]

I wouldn't say this is a problem since you can easily ignore your system's python version by creating virtual environments (which is a good practice too). May I suggest using pyenv with poetry?

[Kenshiro-28]

Thank you, I will try it :)

[mateusscheper]

In my case, my script runs with Python 3.10, so would be great to have 3.10 support. I already tried to downgrade my libs to Python 3.7, but is a major headache, so it would be way simpler to just add 3.10 support to stable-retro.

[arvganesh]

+1 to what @mateusscheper said.