feat: implemented RepeatAction wrapper

[Markus28]

Description

Implements feature request #652. This still needs a unit test.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

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

[Kallinteris-Andreas]

@pseudorndthoughts Do we actually want this feature? In the original issue It was proposed for the use in MuJoCo environments, but MuJoCo already has The frame_skip argument which achieves effectively the same result.

[pseudo-rnd-thoughts]

Thanks for the PR @Markus28
I just realised that this is very similar to MaxAndSkipObservation (

Gymnasium/gymnasium/wrappers/stateful_observation.py

Line 536 in fb5112f

class MaxAndSkipObservation(

)

@Kallinteris-Andreas It is a simple wrapper that might be helpful for users doing Atari style environment details

If we add this, we will need to add tests and to the website wrapper docs

[pseudo-rnd-thoughts]

Add check that num_repeats is an integer (supporting numpy integers)