build: implement dynamic versioning and unified metadata by dmitry-lipetsk · Pull Request #349 · postgrespro/testgres

@dmitry-lipetsk

@dmitry-lipetsk

- Move version to src/__init__.py as the single source of truth
- Update pyproject.toml to use dynamic versioning via setuptools
- Refactor docs/source/conf.py to import version from the package
- Add robust version validation tests using packaging.version

Co-authored-by: Mark G. <mark@google.com>