Update deprecated zuul syntax

Queues are now declared at the project level

https: //lists.openstack.org/pipermail/openstack-discuss/2021-November/025797.html
(cherry picked from commit 56f0110b1ef7a98dac206c92cc65b2a2c519922a)

Manual fix for stable branch: Drop failing lower-constraints job
template, that is mostly dropped from all other projects.

Manual fixes for stable/xena: Dropped lower-constraints removal to avoid
merge conflict. Dropped heat job that no longer exists.

Change-Id: Iae33d7c725274be9de1aa66ad73b2d610c36e061
(cherry picked from commit 6ea92894735adfa63bb8cccc91e4268415a723d8)

.zuul.yaml

@@ -74,6 +74,7 @@
       rally_task: rally-jobs/zaqar-zaqar.yaml
 
 - project:
+    queue: zaqar
     templates:
       - check-requirements
       - openstack-lower-constraints-jobs
@@ -97,12 +98,9 @@
         # If you need any support to debug these jobs in case of
         # failures, please reach us on #tripleo IRC channel.
         - tripleo-ci-centos-7-scenario002-standalone
-        # Heat job that deploy Zaqar
-        - heat-functional-convg-mysql-lbaasv2
         - zaqar-rally:
             voting: false
     gate:
-      queue: zaqar
       jobs:
         - zaqar-tox-integration
         - zaqar-tempest-plugin-mongodb
@@ -110,4 +108,3 @@
         - zaqar-tempest-plugin-swift
         - zaqar-tempest-plugin-swift-ipv6
         - tripleo-ci-centos-7-scenario002-standalone
-        - heat-functional-convg-mysql-lbaasv2