Add Python3 zed unit tests

This is an automatically generated patch to ensure unit testing
is in place for all the of the tested runtimes for zed.

See also the PTI in governance [1].

[1]: https://governance.openstack.org/tc/reference/project-testing-interface.html

Change-Id: Id79fecd4c4b16f2e5c3a5713be50327757346c1a

Author: openstackadmin

.zuul.yaml

@@ -240,7 +240,7 @@
       - osc-tox-unit-tips
       - openstack-cover-jobs
       - openstack-lower-constraints-jobs
-      - openstack-python3-yoga-jobs
+      - openstack-python3-zed-jobs
       - publish-openstack-docs-pti
       - check-requirements
       - release-notes-jobs-python3