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: If0416171105673b6ed031398e41d46257fe113eb
Story: #2002586
Task: #24320

Author: QingsZhao

.zuul.yaml

@@ -194,9 +194,9 @@
       - osc-tox-unit-tips
       - openstack-python-jobs
       - openstack-python35-jobs
-      - publish-openstack-sphinx-docs
+      - publish-openstack-docs-pti
       - check-requirements
-      - release-notes-jobs
+      - release-notes-jobs-python3
       - lib-forward-testing
     check:
       jobs: