Snakeoil

----------------------------

- arghparse: fix compatibility with Python 3.12.7 (Arthur Zamarin)

----------------------------

- arghparse: fix compatibility with Python 3.11.9 (Arthur Zamarin)

----------------------------

- ci: add PyPy3.10, Python 3.12 and Python 3.13 to testing (Sam James, 99)

- fix and update tox.ini (Arthur Zamarin)

- sphinx_ext: support optional email address in authors (Brian Harring)

----------------------------

- remove deprecated ``distutils_extensions`` (Arthur Zamarin, 77)

- enable Python 3.12 support (Sam James, 96)

- drop support for Python 3.9 (Arthur Zamarin)

----------------------------

- cli.arghparse: improve _format_args for Delayed (Arthur Zamarin)
https://github.com/pkgcore/pkgcheck/issues/520

- compression: prefer gtar over tar if available (Sam James, 93)

- format code with ``black`` (Brian Harring, Arthur Zamarin, 95)

----------------------------

- Add constraint satisfaction problem solver (91, Arthur Zamarin)

- dist.sphinxext: mark ``distutils_extensions`` as deprecated. This module will
be removed in the near releases (Arthur Zamarin)

- generate_man_rsts: improve sub-sectioning for sub-commands (Arthur Zamarin)

- generate_man_rsts: better formatting for command line options (Arthur
Zamarin)