URLs entries docs wrong because url() is deprecated

[garyrob]

What are the steps to reproduce this issue?

[Go to https://python-social-auth.readthedocs.io/en/latest/configuration/django.html#urls-entries

What happens?

It shows the use of url(), which is a deprecated function as of Django 3.1.

Expected behaviour

It should use path().

Any other comments?

The current version of the docs are wrong because that code will not work in recent versions of Django.