Make functional jobs voting

Previous patches in the series fixed and enabled actual
notification functional tests, and they pass.

Let's now make them voting to ensure the code is tested
not only by unit tests.

Change-Id: I63afed5f73351e018880bb971cc0c0989abadfe1

.zuul.yaml

@@ -53,7 +53,6 @@
 
 - job:
     name: masakari-functional-devstack-multinode
-    voting: false
     parent: masakari-functional-devstack
     description: |
       Masakari functional tests job based on devstack (two-node).
@@ -61,7 +60,6 @@
 
 - job:
     name: masakari-functional-devstack-multinode-jammy
-    voting: false
     parent: masakari-functional-devstack
     description: |
       Masakari functional tests job based on devstack (Jammy two-node).
@@ -69,7 +67,6 @@
 
 - job:
     name: masakari-functional-devstack-ipv6
-    voting: false
     # NOTE(yoctozepto): The devstack job does not support multinode IPv6 yet.
     parent: masakari-functional-devstack
     description: |