Fix TimeLimit wrapper and add tests

[araffin]

Description

Fix TimeLimit wrapper to allow setting the timeout key inside the env.
Add basic testing that was missing before... (I was surprised there were none :/)

Related to #2752

Note: this fix is needed for properly fixing the car racing env too

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• 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:

• 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
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Note: the test generate a warning but due to the passive env checker on the Pendulul env.

[pseudo-rnd-thoughts]

The bug fix looks good however the tests look like two tests in one.
In addition, it may be easier to use a generic testing environment like the one proposed in #2873 instead of having to override the environment step for the test.

[araffin]

The bug fix looks good however the tests look like two tests in one.

Do you want me to split it into two? one for normal usage and double wrap and one for termination on the last step?

it may be easier to use a generic testing environment like

Feel free to update the test as soon this testing env is merged.
I wrote it that way as it was fast and easy to read (not the cleanest way though).

[pseudo-rnd-thoughts]

Yes, would you be able to split the problem into two
Sure, when the other PR is finalised, I will try to remember to change the environments across

[pseudo-rnd-thoughts]

LGTM