Remove unstable jobs from gating pipeline

Afected jobs:

 - devstack-tobiko-multinode (voting=False)
 - devstacl-tobiko-octavia (voting=False)

Change-Id: Id6ff0c74fd7837709a6f0ce08d2d68bfe0400020

zuul.d/devstack-tobiko-octavia.yaml

@@ -7,9 +7,6 @@
     check:
       jobs:
         - devstack-tobiko-octavia
-    gate:
-      jobs:
-        - devstack-tobiko-octavia
     periodic:
       jobs:
         - devstack-tobiko-octavia

zuul.d/devstack-tobiko.yaml

@@ -11,7 +11,6 @@
     gate: &GATE
       jobs:
         - devstack-tobiko
-        - devstack-tobiko-multinode
     periodic: &PERIODIC
       jobs:
         - devstack-tobiko
@@ -120,7 +119,7 @@
     name: devstack-tobiko-multinode
     parent: devstack-tobiko
     nodeset: devstack-tobiko-multinode
-    voting: true
+    voting: false
     description: Base DevStack Tobiko job with multinode.
     pre-run: playbooks/multinode-setup.yaml
     vars: