Use python job template for Zed

... because the current master should be compatible with the Zed
release of the other projects. This effectively removes testing on
Python 3.6 and only Python 3.8 and 3.9 will be tested.

Python 3.6 and 3.7 are removed form classifiers because these are no
longer supported.

Related-Bug: #1974244
Change-Id: Ibafdb84e5573d74c02874dc0531a6645195a8b5f

setup.cfg

@@ -7,7 +7,7 @@ license = Apache License, Version 2.0
 author = OpenStack
 author_email = openstack-discuss@lists.openstack.org
 home_page = https://docs.openstack.org/python-tripleoclient/latest/
-python_requires = >=3.6
+python_requires = >=3.8
 classifier =
     Environment :: Console
     Environment :: OpenStack
@@ -20,8 +20,6 @@ classifier =
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.6
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
 

zuul.d/layout.yaml

@@ -3,7 +3,7 @@
       - check-requirements
       - openstack-cover-jobs
       - openstackclient-plugin-jobs
-      - openstack-python3-yoga-jobs
+      - openstack-python3-zed-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
       - tripleo-buildimage-jobs
@@ -16,7 +16,7 @@
         - tripleo-ci-centos-9-content-provider:
             dependencies:
               - openstack-tox-pep8
-              - openstack-tox-py36
+              - openstack-tox-py38
               - openstack-tox-py39
         - tripleo-ci-centos-9-standalone:
             vars: