Version 0.4.3

This adds support for CPython 3.12.0b1, and improves Stable ABI / Limited API support (supported by an upcoming nanobind for Python 3.12). An editable install fix allows running from any directory.

Fixes:

• Allow CMake to detect if limited API is targeted by @henryiii in #333 and #342
• Make abi3 support conditional on Python version by @henryiii in #344
• Windows path correction for 3.12.0b1 by @henryiii in #346
• Editable path needs to be absolute by @henryiii in #345

Other:

• Add 3.12.0b1 by @henryiii in #341
• Refactor settings by @henryiii in #338
• Document that CMAKE_ARGS supports space separators by @henryiii in #339

Full Changelog: v0.4.2...v0.4.3