ResourceWarning: unclosed file in create_thumbnail

[cbporch]

The File orig and ContentFile thumb_file variables created in Avatar.create_thumbnail do not appear to be closed before the method returns: https://github.com/jazzband/django-avatar/blob/main/avatar/models.py#L142

Django: 4.1.13
django-avatar: 8.0.0
Python 3.10

While upgrading Django, I noted the following error while running pytest with -Wa flags enabled & PYTHONWARNINGS=always in my env:

/usr/local/lib/python3.10/dist-packages/avatar/models.py:201: ResourceWarning: unclosed file <_io.BufferedReader name='/tmp/tmphkurztys/img/avatar/1/29711aa648bad2dca40e2463dc8761cb.gif'>
  instance.create_thumbnail(size, size)
Enable tracemalloc to get traceback where the object was allocated.
See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

Hopping into a debugger, I can see that by the bottom of the function both have a closed property of False: