Add Python 3.10 support and tests (#9077)

Fixes https://github.com/certbot/certbot/issues/9058.

The changes to the CI config are equivalent to the ones made in https://github.com/certbot/certbot/pull/8460.

Other than ignoring some warnings raised by botocore, the main additional work that had to be done here was switching away from using `distutils.version.LooseVersion` since the entire `distutils` module was deprecated in Python 3.10. To do that, I took a few different approaches:

* If the version strings being parsed are from Python packages such as Certbot or setuptools, I switched to using [pkg_resources.parse_version](https://setuptools.pypa.io/en/latest/pkg_resources.html#parsing-utilities) from `setuptools`. This functionality has been available since [setuptools 8.0 from 2014](https://setuptools.pypa.io/en/latest/history.html#id865).
* If the version strings being parsed are not from Python packages, I added code equivalent to `distutils.version.LooseVersion` in `certbot.util.parse_loose_version`.
* The code for `CERTBOT_PIP_NO_BINARY` can be completely removed since that variable isn't used or referenced anywhere in this repo.

* add python 3.10 support

* make some version changes

* don't use looseversion in setup.py

* switch to pkg_resources

* deprecate get_strict_version

* fix route53 tests

* remove unused CERTBOT_PIP_NO_BINARY code

* stop using distutils in letstest

* add unit tests

* more changelog entries

certbot-nginx/setup.py

@@ -35,6 +35,7 @@ setup(
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
         'Topic :: Internet :: WWW/HTTP',
         'Topic :: Security',
         'Topic :: System :: Installation/Setup',