Release notes for v0.25.2

This is a fairly minor bug fix release.

Bug Fixes

• Removes requirements for _TimeLimit.truncated in info for step compatibility functions. This makes the step compatible with Envpool @arjun-kg
• As the ordering of Dict spaces matters when flattening spaces, updated the __eq__ to account for the .keys() ordering. @XuehaiPan
• Allows CarRacing environment to be pickled. Updated all gym environments to be correctly pickled. @RedTachyon
• seeding Dict and Tuple spaces with integers can cause lower-specification computers to hang due to requiring 8Gb memory. Updated the seeding with integers to not require unique subseeds (subseed collisions are rare). For users that require unique subseeds for all subspaces, we recommend using a dictionary or tuple with the subseeds. @olipinski
• Fixed the metaclass implementation for the new render api to allow custom environments to use metaclasses as well. @YouJiacheng

Updates

• Simplifies the step compatibility functions to make them easier to debug. Time limit wrapper with the old step API favours terminated over truncated if both are true. This is as the old done step API can only encode 3 states (cannot encode terminated=True and truncated=True) therefore we must encode to only terminated=True or truncated=True. @pseudo-rnd-thoughts
• Add Swig as a dependency @kir0ul
• Add type annotation for render_mode and metadata @bkrl