fixed n_relevant_data bug in dispatch_obsgroup

csst_dag/dag/_dispatcher.py

@@ -603,7 +603,7 @@ class Dispatcher:
                     relevant_plan=this_obsgroup_plan,
                     relevant_data=this_obsgroup_file,
                     n_relevant_plan=len(this_obsgroup_plan),
-                    n_relevant_data=this_obsgroup_file,
+                    n_relevant_data=len(this_obsgroup_file),
                     relevant_data_id_list=(
                         []
                         if len(this_obsgroup_file) == 0