Fix pytest collection during test_host partial run (#78594)

Sometimes pytest errors out with an `ImportError` during its tests
collection stage when a Python package/directory containing the test
module does not have an `__init__.py` in it. This is being observed
under Python 3.9 and higher.

The patch provides a workaround for this problem but does not address
the root cause which is currently unknown.

Ref:
https://github.com/ansible/ansible/pull/78585#issuecomment-1220885431
(cherry picked from commit beb70daf14bc14acad076b34dca39a3ca6b633bb)

1 files changed, 0 insertions, 0 deletions

diff --git a/test/units/inventory/__init__.py b/test/units/inventory/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/test/units/inventory/__init__.py