python-bash8 fails to build with Sphinx 2.

it's a Sphinx issue when generating the docs:
BUILDSTDERR: Exception occurred:
BUILDSTDERR:   File "/usr/lib/python3.8/site-packages/oslosphinx/__init__.py", line 76, in builder_inited
BUILDSTDERR:     app.info('Using openstack theme from %s' % theme_dir)
BUILDSTDERR: AttributeError: 'Sphinx' object has no attribute 'info'

This API has been deprecated since Sphinx 1.6 and removed in Sphinx 2.0, you should update to the logging API:
https://www.sphinx-doc.org/en/2.0/extdev/logging.html


This also blocks the rebuild with Python 3.8.
We plan to start 3.8 rebuilds in a side tag this week. The sooner the builds are done, the sooner the side tag can be merged back to rawhide. If the side tag is "open" for too long, it tends to diverge and the merge is more problematic. We usually decide to merge it even if some packages fail to build to prevent that. Once we do, packages that failed to rebuild will fail to install. If you are OK with that, it blocks nothing.