ref-manual: add new python classes

Add brief documentation of python_maturin and python_mesonpy classes
that were added in 5.0.

(From yocto-docs rev: ce7dd61a928dec778a5df538701dfdeb26db0ebd)

Signed-off-by: Paul Eggleton <paul.eggleton@microsoft.com>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/classes.rst

@@ -2380,6 +2380,24 @@ Python modules built with ``flit_core.buildapi`` are pure Python (no
 
 Internally this uses the :ref:`ref-classes-python_pep517` class.
 
+.. _ref-classes-python_maturin:
+
+``python_maturin``
+==================
+
+The :ref:`ref-classes-python_maturin` class provides support for python-maturin, a replacement
+for setuptools_rust and another "backend" for building Python Wheels.
+
+.. _ref-classes-python_mesonpy:
+
+``python_mesonpy``
+==================
+
+The :ref:`ref-classes-python_mesonpy` class enables building Python modules which use the
+meson-python build system.
+
+Internally this uses the :ref:`ref-classes-python_pep517` class.
+
 .. _ref-classes-python_pep517:
 
 ``python_pep517``