Loosen pettingzoo version requirement

[melvintzw]

Is your feature request related to a problem? Please describe.
I am using a tool that depends on a version of pettingzoo (1.22.1) that is higher than the strict requirement (==1.15.0) specified for the mlagents-envs package.

Describe the solution you'd like
I would like to request that mlagents' requirement for pettingzoo is loosened to allow later versions of pettingzoo.

Describe alternatives you've considered
I have considered manually installing and modifying the ml-agents/ml-agents-envs/setup.py to loosen the pettingzoo requirements, but I am not sure what side effects this may have. Is there a particular reason why the pettingzoo requirement was specified strictly as 1.15.0?

Additional context
I am interested to try mlagents v0.30.0 or mlagents v1.0.0, however the pettingzoo requirement specified for mlagents is too restrictive and therefore not compatible with the (higher) pettingzoo version I require. I require a higher version of pettingzoo as my toolkit runs pettingzoo environments that are based on higher versions.

[weichengtao]

They are using the old gym/pettingzoo API which is not compatible with the new API

[github-actions]

This issue is stale because it has been open for 30 days with no activity.

[github-actions]

This issue was closed because it has been inactive for 14 days since being marked as stale. Please open a new issue for related bugs.