Changes to support Python 3.10

There are a few changes required to support Python 3.10:

The test/utils.py module is importing a few types that moved from the collections module to the collections.abc module back in Python 3.3. Those types no longer exist in collections. This problem only affects a small subset of our test suite. The driver itself is fine.

As of Python 3.10 distutils is deprecated, to be removed in Python 3.12. Our setup.py imports a host of features from distutils that will have to be replaced.

https://docs.python.org/3.10/whatsnew/3.10.html#distutils
https://www.python.org/dev/peps/pep-0632/
https://www.python.org/dev/peps/pep-0632/#migration-advice
https://setuptools.readthedocs.io/en/latest/deprecated/distutils-legacy.html

from distutils.cmd import Command

from distutils.command.build_ext import build_ext

from distutils.errors import CCompilerError, DistutilsOptionError

from distutils.errors import DistutilsPlatformError, DistutilsExecError

from distutils.core import Extension

Can be replaced by:

from setuptools import Command

from setuptools.command.build_ext import build_ext

from setuptools.extension import Extension

Note that setuptools doesn't expose the the exception types from distutils.errors or provide a replacement. We'll just catch Exception instead. Catching the explicit distutils exceptions happened way back in the early histlry of PyMongo, but doesn't seem strictly necessary.

Finally, we need to add Python 3.10 to the test matrix.