Fix falcon tokenization step (#1441) [skip ci]

* Fix falcon tokenization step

* chore: lint

---------

Co-authored-by: Wing Lian <wing.lian@gmail.com>

src/axolotl/utils/trainer.py

@@ -124,9 +124,10 @@ def process_datasets_for_packing(cfg, train_dataset, eval_dataset):
                 eval_dataset = eval_dataset.remove_columns("attention_mask")
 
         if cfg.model_config_type == "falcon":
-            LOG.info("dropping token_type_ids column")
-            train_dataset = train_dataset.remove_columns("token_type_ids")
-            if eval_dataset:
+            LOG.info("dropping token_type_ids column if it exists")
+            if "token_type_ids" in train_dataset.column_names:
+                train_dataset = train_dataset.remove_columns("token_type_ids")
+            if eval_dataset and "token_type_ids" in eval_dataset.column_names:
                 eval_dataset = eval_dataset.remove_columns("token_type_ids")
 
         train_dataset = train_dataset.filter(