* chore: add pyproject toml configuration
* build: migrate RapidOCR wheel packaging to pyproject.toml
- add PEP 517 setuptools build configuration
- derive package version from git tags via setuptools-scm
- move wheel model preparation into an explicit tools script
- generate MANIFEST.in for default model assets before building
- avoid importing rapidocr during package metadata generation
* ci: build release wheels from validated git tags
* build: align package runtime support with Python 3.8
- set Requires-Python to >=3.8
- remove Python 3.6 and 3.7 classifiers
- make wheel asset preparation script type hints Python 3.8 compatible
- clarify split between build-time and wheel runtime support
SWHL