[v2] Use EXPECT instead of On in `queue`

[machichima]

The only place with On() left is in queue/service/queue_service_test.go. Will need a few refactor there. I think we can do it in the follow-up PR

❯ find ./ -name "*_test.go" -type f -exec grep -l "\.On(" {} \;
./queue/service/queue_service_test.go

1. Current queue_service_test.go define the mock implementation manually. We should use mockery instead, following how we generate mocks in [v2] Refactor: Define all mockery in .mockery.yaml #6829:

   flyte/queue/service/queue_service_test.go

   Lines 18 to 20 in ada62dc

   	type MockQueueClient struct {
   	mock.Mock
   	}

2. Use EXPECT instead of On following the mockery best practice

Originally posted by @machichima in #6829 (review)

[WangWang0226]

#take