https://www.pywikibot.org ships the last stable and the last master release as well as the python2 branch (release 3.0.20200703) of Pywikibot. Python 2 life cycle has ended for four years [1] and 5 % of bot edits based on Pywikibot framework are still running with Python 2.7 [2].
But there are no new releases for Python 2.7 and nobody needs to update it, nobody should use Pywikibot 3 / Python 2 anymore and it is recommended to use the current stable release instead. Due to T291202 the minimal needed Pywikibot release for the current MW is probably 6.6.1.
Therefore I propose to remove Pywikibot release 3.0.20200703 supporting Python 2 from nightly build. Using svn or git repository is the better way anyway.
See also T244955.