[RLlib] Eval workers use async req manager.

rllib/execution/parallel_requests.py

@@ -13,7 +13,7 @@ class AsyncRequestsManager:
 
  Args:
  workers: A list of ray remote workers to operate on. These workers must have an
- `apply` method which takes a function and a list of arguments to that
+ ``apply`` method which takes a function and a list of arguments to that
  function.
  max_remote_requests_in_flight_per_worker: The maximum number of remote
  requests that can be in flight per actor. Any requests made to the pool