switch documentation job to new PTI

This is a mechanically generated patch to switch the documentation
jobs to use the new PTI versions of the jobs as part of the
python3-first goal.

See the python3-first goal document for details:
https://governance.openstack.org/tc/goals/stein/python3-first.html

Change-Id: I5ed727f3dd33ad1c08de34b24246bd78b260dc8c
Story: #2002586
Task: #24298

.zuul.yaml

@@ -1,11 +1,11 @@
 - project:
     templates:
       - check-requirements
-      - publish-openstack-sphinx-docs
+      - publish-openstack-docs-pti
       - openstack-python-jobs-horizon
       - openstack-python35-jobs-horizon
       - nodejs4-jobs
-      - release-notes-jobs
+      - release-notes-jobs-python3
     check:
       jobs:
         - openstack-tox-lower-constraints