graphics/py-cairo: unbreak with python310

import cairo

Traceback (most recent call last):

File "<stdin>", line 1, in <module>
File "/usr/local/lib/python3.10/site-packages/cairo/__init__.py", line 1, in <module>
  from ._cairo import *  # noqa: F401,F403

ImportError: /usr/local/lib/python3.10/site-packages/cairo/_cairo.cpython-310.so: Undefined symbol "PyObject_AsReadBuffer"
ImportError: /usr/local/lib/python3.10/site-packages/cairo/_cairo.cpython-310.so: Undefined symbol "PyObject_AsWriteBuffer"