Merge openstack-ansible skip-if to resolve conflict

The current rules have a conflicting match, resulting in the skip-if
for the docs jobs never taking effect.

This patch merges both skip-if rules so that if any patches contain
docs and/or release notes and nothing else, then only those jobs will
run.

The purpose of this skip is to save the unnecessary consumption of
nodepool nodes.

Change-Id: Idc3c9d06c503d3e84395e193345023c9aeab21c6

zuul/layout.yaml

@@ -1995,19 +1995,14 @@ jobs:
   - name: gate-networking-hyperv-python34
     branch: ^(?!stable/kilo).*$
 
-  # skip all openstack-ansible jobs except the docs job for rst/doc files
-  - name: ^gate-openstack-ansible-(?!docs).*$
+  # skip all openstack-ansible jobs except the releasenotes/docs
+  # jobs for rst/doc/releasenotes files
+  - name: ^gate-openstack-ansible-(?!(docs|releasenotes)).*$
     skip-if:
       - project: ^openstack/openstack-ansible$
         all-files-match-any:
           - ^.*\.rst$
           - ^doc/.*
-
-  # skip all openstack-ansible jobs except the releasenotes job for releasenotes
-  - name: ^gate-openstack-ansible-(?!releasenotes).*$
-    skip-if:
-      - project: ^openstack/openstack-ansible$
-        all-files-match-any:
           - ^releasenotes/.*
 
   # skip the new ubuntu-trusty based commit check for the juno