fix: Omnichannel queue starting multiple times due to race condition (#34062)

.changeset/green-shirts-fold.md

apps/meteor/server/services/omnichannel/queue.ts

apps/meteor/server/services/omnichannel/service.ts

packages/core-services/src/index.ts

packages/core-services/src/lib/ServiceStarter.ts

packages/core-services/tests/ServiceStarter.test.ts