4.2.0 breaks keyring

We use `keyring` and over the last couple of days our app that uses keyring fails to start due to the stacktrace below.

Troubleshooting this issue, the problem is evident since the release of 4.2.0.

If I version lock `jaraco.functools==4.1.0` (to avoid 4.2.0 with the above commit) keyring works as expected.

```
import pkg_resources
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 3259, in
@_call_aside
^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 3234, in _call_aside
f(*args, **kwargs)
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 3272, in _initialize_master_working_set
working_set = WorkingSet._build_master()
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 583, in _build_master
return cls._build_from_requirements(__requires__)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 596, in _build_from_requirements
dists = ws.resolve(reqs, Environment())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.11/site-packages/pkg_resources/__init__.py", line 795, in resolve
raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'jaraco.functools' distribution was not found and is required by keyring
```

For the record 'jaraco.functools' is present and installed and I can manually load it.

No files or tests are named. Start by reproducing the failure with jaraco.functools 4.2.0 and reviewing the changes between 4.1.0 and 4.2.0; done means keyring starts successfully with 4.2.0 installed and a regression test covers the reported DistributionNotFound error.

Written by the indexing model from the issue text.