Python 2.6 is not supported by PSF since 2013-10-29.
Python 3.3 reached it's EOL on 2017-09-19. Packages have already started to
drop support for it.
It's a burden for developers keep the tests passing for these python
versions. And, I believe, for contributors to keep the code backward
If anyone objects, or really needs to run pywikibot with these versions,
please reply to this email or leave a comment on T154771.
: [RfC] Abandon support for Python 2.6