These translation sections are not needed anymore, Babel can
generate translation files without them.
Remove babel.cfg as well, this is the default role and not needed
anymore.
also remove Babel from requirements[1]
[1] http://lists.openstack.org/pipermail/openstack-discuss/2020-April/014227.html
Change-Id: Iead96312102da530a006fc259bab80ad37e55b76