Correct queue declaration in Zuul config

Move the ec2-api queue declaration from the pipeline level (where it
is no longer valid) to the project level.

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

Change-Id: I3103c4ecb803e784c87ed4cff5124d303620d4a5

.zuul.yaml

@@ -1,4 +1,5 @@
 - project:
+    queue: ec2-api
     templates:
       - check-requirements
       - openstack-python3-jobs