migrate to gymnasium

[rodrigodelazcano]

Description

Use Gymnasium >=v0.26 instead of gym.

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Screenshots

Please attach before and after screenshots of the change if applicable.

Checklist:

• [x] I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[pseudo-rnd-thoughts]

Will this be a v2 or v1.3?

[rodrigodelazcano]

Will this be a v2 or v1.3?

I will go directly with v2 since gymnasium is a major dependency update. The v1 versions will reference all the changes made under gym and with v2 all the ones that correspond to gymnasium