Merge pull request #3363 from babsey/fix-nest-server-mpi

Fix nest-server-mpi

Author: jessica-mitchell

bin/nest-server-mpi

@@ -73,4 +73,4 @@ else:
                 continue
 
         log(call_name, f"sending reponse gather, data={response}")
-        comm.gather(nest.serializable(response), root=0)
+        comm.gather(nest.serialize_data(response), root=0)