Remove redundant word in worker logging

```
[cloud-app-worker-k8s] DEBUG:procrastinate.worker.worker:Waiting for new jobs on queues queues k8s
[cloud-app-worker-email] DEBUG:procrastinate.worker.worker:Waiting for new jobs on queues queues email
```

One too many "queues"!

procrastinate/worker.py

@@ -148,7 +148,7 @@ async def single_worker(self, worker_id: int):
     async def wait_for_job(self, timeout: float):
         assert self.notify_event
         self.logger.debug(
-            f"Waiting for new jobs on queues " f"{self.base_context.queues_display}",
+            f"Waiting for new jobs on " f"{self.base_context.queues_display}",
             extra=self.base_context.log_extra(
                 action="waiting_for_jobs", queues=self.queues
             ),