DeprecationWarning for use of legacy `importlib_resources` API

[bskinn]

I'm seeing a DeprecationWarning in my tox matrix for bskinn/sphobjinv running with Python 3.11.0a4, which appears to be due to certifi's use of a legacy API from importlib_resources.

In a fresh virtual environment:

$ python -V -V
Python 3.11.0a4 (main, Jan 14 2022, 20:31:59) [GCC 10.2.1 20210110]

$ pip install certifi
Collecting certifi
  Using cached certifi-2021.10.8-py2.py3-none-any.whl (149 kB)
Installing collected packages: certifi
Successfully installed certifi-2021.10.8

$ pip list
Package    Version
---------- ---------
certifi    2021.10.8
pip        21.3.1
setuptools 60.2.0
wheel      0.37.1

$ python -W 'error' -c 'import certifi; certifi.where()'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File ".../lib/python3.11/site-packages/certifi/core.py", line 36, in where
    _CACERT_CTX = get_path("certifi", "cacert.pem")
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../python/3.11.0a4/lib/python3.11/importlib/resources/_legacy.py", line 18, in wrapper
    warnings.warn(
    ^^^^^^^^^^^^^^
DeprecationWarning: path is deprecated. Use files() instead. Refer to https://importlib-resources.readthedocs.io/en/latest/using.html#migrating-from-legacy for migration advice.

Seems like it should be a pretty simple port to the new API. I'd be happy to attempt a PR if it's of interest.

[bskinn]

Whoops, didn't check the closed issues first. Sorry!