docs: Add new modules swh.auth and swh.counters
Adding the missing swh.auth[django] for the deposit build so now it's fine. At the same time, add also the reference to the new swh.counters.
This should fix the build, it did locally.
Related to #3172 (closed)
Test Plan
tox -e sphinx is happy
Migrated from D5327 (view on Phabricator)