0.23.1

This release contains a few small bug fixes and no breaking changes.

• Make VideoRecorder backward-compatible to gym<0.23 by @vwxyzjn in #2678
• Fix issues with pygame event handling (which should fix support on windows and in jupyter notebooks) by @andrewtanJS in #2684
• Add py.typed to package_data by @micimize in https://github.com/openai/gym/p
• Fixes around 1500 warnings in CI @pseudo-rnd-thoughts
• Deprecation warnings correctly display now @vwxyzjn
• Fix removing striker and thrower @RushivArora
• Fix small dependency warning errorr @ZhiqingXiao