Development changes

For Matplotlib 3.6, the :ref:`minimum supported versions <dependencies>` are
being bumped:

+------------+-----------------+---------------+
| Dependency |  min in mpl3.5  | min in mpl3.6 |
+============+=================+===============+
|   Python   |       3.7       |      3.8      |
+------------+-----------------+---------------+
|   NumPy    |       1.17      |      1.19     |
+------------+-----------------+---------------+

This is consistent with our :ref:`min_deps_policy` and `NEP29
<https://numpy.org/neps/nep-0029-deprecation_policy.html>`__

Build setup options changes
~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``gui_support.macosx`` setup option has been renamed to
``packages.macosx``.

New wheel architectures
~~~~~~~~~~~~~~~~~~~~~~~

Wheels have been added for:

- Python 3.11
- PyPy 3.8 and 3.9

Increase to required versions of documentation dependencies