Drop master-only job from zuul config

The tips job should only run on the master branch, drop it from the zuul
config for stable branches.

Updated for zed and older: Drop openstack-lower-constraints-jobs

Change-Id: Ic2ddb04bc1f1e81586fff54f1e7bee9ee3689512
(cherry picked from commit 923a847dea)

.zuul.yaml

@@ -2,7 +2,6 @@
 - project:
     templates:
       - check-requirements
-      - openstack-lower-constraints-jobs
       - openstack-python3-zed-jobs
       - osc-tox-unit-tips
       - publish-openstack-docs-pti
@@ -12,13 +11,6 @@
         - osc-functional-devstack:
             required-projects:
               - openstack/python-openstackclient
-        - osc-functional-devstack-tips:
-            voting: false
-            # The functional-tips job only tests the latest and shouldn't be run
-            # on the stable branches
-            branches: ^(?!stable)
-            required-projects:
-              - openstack/python-openstackclient
     gate:
       jobs:
         - osc-functional-devstack: