throw for IQueryable used as an IEnumerable (#975)

* Revert "force a ToList in Filter in case IEnumerable result is an open data reader (#974)"

This reverts commit a7f3520.

* throw for IQueryable used as an IEnumerable

src/GraphQL.EntityFramework/Filters/Filters.cs

@@ -60,6 +60,11 @@ internal virtual async Task<IEnumerable<TEntity>> ApplyFilter<TEntity>(IEnumerab
             return result;
         }
 
+        if (result is IQueryable)
+        {
+            throw new("This API expects the resolver to return a IEnumerable, not an IQueryable. Instead use AddQuery*");
+        }
+
         var list = new List<TEntity>();
         foreach (var item in result)
         {