feat: Drop Python 3.8 Support, Add Python 3.12 Support

[mbsantiago]

This PR updates the project's Python version support by:

• Dropping support for Python 3.8: Python 3.8 has reached its end-of-life (EOL) and is no longer receiving security updates or bug fixes.
• Adding support for Python 3.12: Python 3.12 is now sufficiently mature, with all project dependencies providing compatible versions. This allows us to leverage the latest features and performance improvements in Python 3.12.

The pyproject.toml metadata has been updated to reflect these changes, and the uv.lock file has been regenerated to include Python versions 3.9 through 3.12.