Fix deprecated zuul queue syntax

Zuul deprecated (and now removed) declaring shared queues at a pipeline
level [1]. This patch fixes the syntax to make the gate work again for
monasca-common.

[1] https://lists.openstack.org/pipermail/openstack-discuss/2022-May/028603.html

Change-Id: Id9c0956d4800f01dadfece02638bc4fcc9ef1e8a

.zuul.yaml

@@ -1,4 +1,5 @@
 - project:
+    queue: monasca
     templates:
       - check-requirements
       - openstack-cover-jobs
@@ -12,7 +13,6 @@
         - monascalog-tempest
         - legacy-monasca-common-maven-build
     gate:
-      queue: monasca
       jobs:
         - monasca-tempest-python3-influxdb:
             voting: false