Use publish-to-pypi everywhere
Use publish-to-pypi everywhere

Now publish-to-pypi and publish-to-pypi-python3 are the same jobs, so we
can use publish-to-pypi everywhere.

Needed-By: https://review.openstack.org/615241
Depends-On: https://review.openstack.org/615237
Change-Id: I62a694885591cd4d93d1de7f1c82053b3762b6c1

openstack-infra/project-config,openstack-infra/project-config