Fix awxkit tox test failure caused by root pytest.ini config bleed (#16520)

Forward-port of ansible/tower#7537 for the devel branch.

When running awxkit's tox tests, pytest picks up the root pytest.ini
which pulls in pytest-django options (--reuse-db, --nomigrations,
DJANGO_SETTINGS_MODULE) and Django-specific filterwarnings.  Since the
awxkit tox environment does not install Django or pytest-django, these
cause test collection to fail.

The root cause is that pytest.ini has absolute priority in pytest's
config discovery — it searches all ancestor directories for pytest.ini
before falling back to tox.ini's [pytest] section.  A [pytest] section
in awxkit/tox.ini alone cannot prevent the root config from being used.

Fix by:
- Adding awxkit/pytest.ini to act as the primary config boundary
  (pytest.ini has the highest priority in config discovery, so its
  presence in awxkit/ stops the upward search before reaching root)
- Adding explicit `test` path argument to the pytest command in
  awxkit/tox.ini so pytest discovers tests correctly
- Adding `testpaths` and `python_files` to the [pytest] section in
  awxkit/tox.ini as a secondary config boundary
- Adding awxkit/conftest.py that registers the Django-specific CLI
  options and INI keys as harmless no-ops, as a further safety net

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

awxkit/pytest.ini

@@ -0,0 +1,9 @@
+[pytest]
+addopts = -v --tb=native
+testpaths = test
+python_files = test_*.py
+
+filterwarnings =
+  error
+
+junit_family=xunit2