Updated gym version requirement to 0.21.*

[Axle7XStriker]

This update is required by https://github.com/AlignmentResearch/rllf to depend on magical and create custom environments for their research. However, it doesn't make any significant updates but rather updates the gym version requirement for magical which seems to pass the current test suite.

[qxcv]

Thanks for the PR. Unfortunately when I try to install I get this error:

$ pip install -e .
Obtaining file:///home/sam/repos/magical-pr
  Preparing metadata (setup.py) ... done
Collecting pymunk~=5.6.0
  Using cached pymunk-5.6.0-py2.py3-none-manylinux1_x86_64.whl (535 kB)
Collecting pyglet==1.5.*
  Using cached pyglet-1.5.27-py3-none-any.whl (1.1 MB)
Collecting gym==0.21.*
  Using cached gym-0.21.0.tar.gz (1.5 MB)
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [1 lines of output]
      error in gym setup command: 'extras_require' must be a dictionary whose values are strings or lists of strings containing valid project/version requirement specifiers.
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

I have:

$ python --version
Python 3.8.16
$ pip --version
pip 23.0.1 from /home/sam/.../pip (python 3.8)

Any idea what might be causing this?

[Axle7XStriker]

Try downgrading setuptools version to <=v65.5.0. The later versions throw this error.