www/py-django-reversion: Update to 6.1.0

• Switch to the PEP517 build framework and adjust the related bits of DOCS option as well.

• Update WWW to point to actual upstream repository.

• Also switch to the more preferred DISTVERSION and take MAINTAINER'ship due three consecutive timeouts.

Changelog since 5.0.10:

https://github.com/etianen/django-reversion/blob/v6.1.0/CHANGELOG.rst

PR: 291709
Approved by: maintainer timeout (5+ weeks)