Simplify past_key_values handling in PreTrainedModel for beam search

Author: justsml

packages/transformers/src/models/modeling_utils.js

@@ -1448,14 +1448,7 @@ export class PreTrainedModel extends Callable {
         }
 
         if (generation_config.return_dict_in_generate) {
-            let past_key_values_for_return = past_key_values;
-            if (is_beam_search) {
-                console.warn(
-                    'Beam search does not return aligned past_key_values for finalized sequences. ' +
-                        'past_key_values will be null; re-generate without beam search if you need caching.',
-                );
-                past_key_values_for_return = null;
-            }
+            const past_key_values_for_return = is_beam_search ? null : past_key_values;
             return {
                 sequences,
                 past_key_values: past_key_values_for_return,