Fix undefined LlamaForCausalLM and del try except

src/axolotl/utils/models.py

@@ -81,7 +81,6 @@ def load_model(
     Load a model from a base model and a model type.
     """
 
-    global LlamaForCausalLM  # pylint: disable=global-statement
     # TODO refactor as a kwarg
     load_in_8bit = cfg.load_in_8bit
     cfg.is_llama_derived_model = "llama" in base_model or (
@@ -203,12 +202,7 @@ def load_model(
             )
             load_in_8bit = False
         elif cfg.is_llama_derived_model:
-            try:
-                from transformers import LlamaForCausalLM
-            except ImportError:
-                logging.warning(
-                    "This version of transformers does not support Llama. Consider upgrading."
-                )
+            from transformers import LlamaForCausalLM
 
             config = LlamaConfig.from_pretrained(base_model_config)
             model = LlamaForCausalLM.from_pretrained(