⚙️ Adds Django 4.2 support and fixes trove classifiers

[jefftriplett]

This just checks a few boxes to get trove classifiers and CI testing...

I'm seeing a few warnings, but things are passing now (some of the RemovedInDjango51Warning might require dropping 2.2 support):

../../lib/python3.10/site-packages/kombu/utils/compat.py:82
tests/test_celery_ping.py::TestCeleryPingHealthCheck::test_check_status_doesnt_add_errors_when_ping_successful
  /Users/jefftriplett/.virtualenvs/django-health-check/lib/python3.10/site-packages/kombu/utils/compat.py:82: DeprecationWarning: SelectableGroups dict interface is deprecated. Use select.
    for ep in importlib_metadata.entry_points().get(namespace, [])

../../lib/python3.10/site-packages/django/conf/__init__.py:193
  /Users/jefftriplett/.virtualenvs/django-health-check/lib/python3.10/site-packages/django/conf/__init__.py:193: RemovedInDjango51Warning: The DEFAULT_FILE_STORAGE setting is deprecated. Use STORAGES instead.
    self._show_deprecation_warning(

tests/test_storage.py::HealthCheckStorageTests::test_get_storage
  /Users/jefftriplett/.virtualenvs/django-health-check/lib/python3.10/site-packages/django/core/files/storage/__init__.py:32: RemovedInDjango51Warning: django.core.files.storage.get_storage_class is deprecated in favor of using django.core.files.storage.storages.
    warnings.warn(GET_STORAGE_CLASS_DEPRECATED_MSG, RemovedInDjango51Warning)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html