Fallback for missing attribute `Parameter.ds_numel` (#24942)

* [trainer] fallback for deepspeed param count

* [trainer] more readable numel count

src/transformers/trainer_pt_utils.py

@@ -1043,7 +1043,7 @@ def get_model_param_count(model, trainable_only=False):
     if is_deepspeed_zero3_enabled():
 
         def numel(p):
-            return p.ds_numel
+            return p.ds_numel if hasattr(p, "ds_numel") else p.numel()
 
     else: