models.py -> loaders/ module refactor (#2680)

* models.py -> loaders/ module refactor

* refactor ModelLoader class

* plugin manager changes

* circular import fix

* pytest

* pytest

* minor improvements

* fix

* minor changes

* fix test

* remove dead code

* coderabbit comments

* lint

* fix

* coderabbit suggestion I liked

* more coderabbit

* review comments, yak shaving

* lint

* updating in light of SP ctx manager changes

* review comment

* review comment 2

tests/e2e/patched/test_model_patches.py

@@ -6,9 +6,9 @@ import unittest
 
 import transformers
 
+from axolotl.loaders import ModelLoader, load_tokenizer
 from axolotl.utils.config import normalize_config, validate_config
 from axolotl.utils.dict import DictDefault
-from axolotl.utils.models import load_model, load_tokenizer
 
 from ..utils import with_temp_dir
 
@@ -50,7 +50,7 @@ class TestModelPatches(unittest.TestCase):
         cfg = validate_config(cfg)
         normalize_config(cfg)
         tokenizer = load_tokenizer(cfg)
-        load_model(cfg, tokenizer, inference=False)
+        ModelLoader(cfg, tokenizer, inference=False).load()
 
     @with_temp_dir
     def test_mistral_multipack(self, temp_dir):
@@ -83,7 +83,7 @@ class TestModelPatches(unittest.TestCase):
         cfg = validate_config(cfg)
         normalize_config(cfg)
         tokenizer = load_tokenizer(cfg)
-        load_model(cfg, tokenizer, inference=False)
+        ModelLoader(cfg, tokenizer, inference=False).load()
 
         assert (
             "torch.jit"