* Remove additional ignores from flake8
* Remove all unused imports
* Remove all unused imports
* Update flake8 and pyupgrade
* F841, removed unused variables
* E731, removed lambda assignment to variables
* Remove E731, F403, F405, F524
* Remove E722, bare exceptions
* Remove E712, compare variable == True or == False to is True or is False
* Remove E402, module level import not at top of file
* Added --pre-file-ignores
* Add --per-file-ignores removing E741, E302 and E704
* Add E741, do not use variables named ‘l’, ‘O’, or ‘I’ to ignore issues in classic control
* Fixed issues for pytest==6.2
* Remove unnecessary # noqa
* Edit comment with the removal of E302
* Added warnings and declared module, attr for pyright type hinting
* Remove unused import
* Removed flake8 E302
* Updated flake8 from 3.9.2 to 4.0.1
* Remove unused variable
* initial draft of optional info dict in reset function, implemented for cartpole, tests seem to be passing
* merged core.py
* updated return type annotation for reset function in core.py
* optional metadata with return_info from reset added for all first party environments, with corresponding tests. Incomplete implementation for wrappers and vector wrappers
* removed Optional type for return_info arguments
* added tests for return_info to normalize wrapper and sync_vector_env
* autoformatted using black
* added optional reset metadata tests to several wrappers
* added return_info capability to async_vector_env.py and test to verify functionality
* added optional return_info test for record_video.py
* removed tests for mujoco environments
* autoformatted
* improved test coverage for optional reset return_info
* re-removed unit test envs accidentally reintroduced in merge
* removed unnecessary import
* changes based on code-review
* small fix to core wrapper typing and autoformatted record_epsisode_stats
* small change to pass flake8 style