Clean up pyproject.toml after Poetry-to-uv migration

- Remove build-system (hatchling) and hatch targets — not needed for
  a non-published test framework
- Remove PyPI classifiers (irrelevant without publishing)
- Add pythonpath = ["src"] to pytest config to fix ModuleNotFoundError
  without requiring an editable install
- Bump faker 40.4.0 -> 40.5.1 (patch update)
- Remove stale poetry.toml entry from .gitignore
- Bump version to 0.2.0