Define queues at project level

Defining queues at project.pipeline level was deprecated in release
4.1.0 of Zuul [1] and support for it will (probably) be dropped in
release 7.0.0. [2][3]

[1] https://zuul-ci.org/docs/zuul/latest/releasenotes.html#relnotes-4-1-0-deprecation-notes
[2] https://lists.openstack.org/pipermail/openstack-discuss/2022-May/028603.html
[3] https://lists.zuul-ci.org/pipermail/zuul-discuss/2022-May/001801.html

Signed-off-by: Eduardo Santos <eduardo.experimental@gmail.com>
Change-Id: Ife023187f307f1190d5e76daf644db0b5cd55d38

zuul.d/project.yaml

@@ -6,6 +6,7 @@
       - check-requirements
       - release-notes-jobs-python3
       - periodic-stable-jobs
+    queue: manila
     check:
       jobs:
         - manila-tox-genconfig
@@ -40,7 +41,6 @@
         - manila-rally-ss:
             voting: false
     gate:
-      queue: manila
       jobs:
         - manila-tempest-plugin-dummy-no-dhss
         - manila-tempest-plugin-dummy-dhss