Use current openstack tests

Change-Id: If8fb44687415137ac3abde09b6f168b54eb30624

.zuul.yaml

@@ -1,5 +1,19 @@
 - project:
     templates:
       - check-requirements
-      - openstack-python3-xena-jobs
+      - openstack-python3-yoga-jobs
       - publish-openstack-docs-pti
+    check:
+      jobs:
+        # NOTE(rpittau): yoga jobs support py38 and py39 but we want to keep
+        # testing py36 to maintain compatibility with older distributions like
+        # CentOS Stream 8, Ubuntu Bionic, Debian 10, and openSuse Leap
+        # Remove after Yoga
+        - openstack-tox-py36
+    gate:
+      jobs:
+        # NOTE(rpittau): yoga jobs support py38 and py39 but we want to keep
+        # testing py36 to maintain compatibility with older distributions like
+        # CentOS Stream 8, Ubuntu Bionic, Debian 10, and openSuse Leap
+        # Remove after Yoga
+        - openstack-tox-py36