Ubuntu: add upgrade jobs to gate

Follow up to I69868dca6e1f3e4a1bf123c9e7f1f3412162b264

Change-Id: I7812c4b66bac30648c00054381703e390671a821

zuul.d/project.yaml

@@ -36,8 +36,10 @@
         - kayobe-overcloud-host-configure-centos8s
         - kayobe-overcloud-host-configure-ubuntu-focal
         - kayobe-overcloud-upgrade-centos8s
+        - kayobe-overcloud-upgrade-ubuntu-focal
         - kayobe-seed-centos8s
         - kayobe-seed-ubuntu-focal
         - kayobe-seed-upgrade-centos8s
+        - kayobe-seed-upgrade-ubuntu-focal
         - kayobe-seed-vm-centos8s
         - kayobe-seed-vm-ubuntu-focal