match up gradient checkpointing when using lora w config

src/axolotl/utils/models.py

@@ -305,7 +305,9 @@ def load_model(
         or (cfg.adapter == "qlora" and cfg.load_in_4bit)
     ):
         logging.info("converting PEFT model w/ prepare_model_for_kbit_training")
-        model = prepare_model_for_kbit_training(model)
+        model = prepare_model_for_kbit_training(
+            model, use_gradient_checkpointing=cfg.gradient_checkpointing
+        )
 
     model, lora_config = load_adapter(model, cfg, adapter)