Snakeoil

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

- compression: add parallel xz support (83, Sam James, Arthur Zamarin)

- various improvements for the build system (Arthur Zamarin)

- drop support for python 3.8 (Arthur Zamarin)

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

- test/mixins: remove ``mk_named_tempfile``. Use ``tmp_path / [filename]``
instead (Arthur Zamarin)

- fileutils: remove deprecated ``write_file``. Use ``Path().write_text``
instead (Arthur Zamarin)

- fileutils: remove deprecated ``UnbufferedWriteHandle``. Use
``io.TextIOWrapper`` with ``write_through=True`` instead (Arthur Zamarin)

- descriptors: remove unused ``classproperty`` (Arthur Zamarin)

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

This release has various breaking changes, with various deprecated stuff
removed. We are planing to remove more cruft in the future, so please be aware.
All removals will be listed in the release notes, and a better replacement will
be provided.

This is also the first release to use ``flit`` for packaging, which simplifies
the build a lot. We include a makefile for convenience of running various build
commands. Please speak to us if they do not suit your needs.

- ``dist.distutils_extensions`` is now **deprecated**, and will be removed in
the future.

- klass: add typing for ``jit_attr*`` funcitons (Arthur Zamarin)

- stringio: remove ``text_writable`` and ``bytes_writable``. Use
``io.StringIO`` and ``io.BytesIO`` instead (Arthur Zamarin)

- remove ``TempDirMixin`` and ``tempdir_decorator``. Use ``tempdir`` instead
(Arthur Zamarin)

- remove cython files, as regular Python code was fast enough and the
performance difference was negligible (Arthur Zamarin)

- remove ``mk_cpy_loadable_testcase``. Use parameterized arguments in pytest
instead (Arthur Zamarin)

- remove ``TestCase``. Use pytest's ``assert`` instead (Arthur Zamarin)

- version: better locale protection around running git (Arthur Zamarin)

- migrate to ``flit`` packaging and universal wheels (Arthur Zamarin)

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

- distutils_extensions: fix pip detection for editable installs (Arthur
Zamarin)

- ci: Update cibuildwheel - should fix generation of wheels for CPython 3.10
and PyPy 3.9 (Arthur Zamarin)

- fix and port snakeoil to Python 3.11 (Arthur Zamarin, Sam James, 73)

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

- Remove ``TempDir`` and ``RandomPath`` test fixtures. In case you used those
those fixtures, migrate to ``tmp_path`` and ``tmp_path / random_str(10)``
(Arthur Zamarin, 66)

- osutil: ``sizeof_fmt()`` improvements and tests addition (Michał Górny, 67)

- Fix distutils extension compatibility with setuptools. (Sam James, Arthur
Zamarin)

- Force newer required version of ``cython``, so a Python 3.11 compatible
``.c`` is generated (Arthur Zamarin)

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

- Fix distutils extension compatibility with setuptools 60.