Fix reference to run_batch in run_batch_async docs (quantumlib#5740)

Follow-up to quantumlib#5555 to fix docs.

Author: maffoo

Diff for: cirq-core/cirq/work/sampler.py

@@ -287,9 +287,9 @@ async def run_batch_async(
         params_list: Optional[Sequence['cirq.Sweepable']] = None,
         repetitions: Union[int, Sequence[int]] = 1,
     ) -> Sequence[Sequence['cirq.Result']]:
-        """Runs the supplied circuits.
+        """Runs the supplied circuits asynchronously.
 
-        This is an asynchronous version of `run_batch`; see full docs there.
+        See docs for `cirq.Sampler.run_batch`.
         """
         params_list, repetitions = self._normalize_batch_args(programs, params_list, repetitions)
         return [