Mark rolling-upgrade job voting again

We got fixes everwhere we needed; this actually could have been voting
a while back.

Related-Change: https://review.opendev.org/c/openstack/swift/+/863929
Change-Id: I86012f7f4703becfbc6bb59b865a123cc9823f77

.zuul.yaml

@@ -757,7 +757,6 @@
               - ^doc/(requirements.txt|(saio|s3api|source)/.*)$
         - swift-multinode-rolling-upgrade:
             irrelevant-files: *functest-irrelevant-files
-            voting: false
         - tempest-integrated-object-storage:
             irrelevant-files: &tempest-irrelevant-files
               - ^(api-ref|doc|releasenotes)/.*$
@@ -804,6 +803,8 @@
             irrelevant-files: *unittest-irrelevant-files
         - openstack-tox-pep8:
             irrelevant-files: *pep8-irrelevant-files
+        - swift-multinode-rolling-upgrade:
+            irrelevant-files: *functest-irrelevant-files
         - tempest-integrated-object-storage:
             irrelevant-files: *tempest-irrelevant-files
         - tempest-ipv6-only: