[Refactor] Update from single file

src/diffusers/loaders/__init__.py

@@ -54,12 +54,11 @@ def text_encoder_attn_modules(text_encoder):
 _import_structure = {}
 
 if is_torch_available():
-    _import_structure["single_file"] = ["FromOriginalControlnetMixin", "FromOriginalVAEMixin"]
     _import_structure["unet"] = ["UNet2DConditionLoadersMixin"]
     _import_structure["utils"] = ["AttnProcsLayers"]
 
     if is_transformers_available():
-        _import_structure["single_file"].extend(["FromSingleFileMixin"])
+        _import_structure["single_file"] = ["FromSingleFileMixin"]
         _import_structure["lora"] = ["LoraLoaderMixin", "StableDiffusionXLLoraLoaderMixin"]
         _import_structure["textual_inversion"] = ["TextualInversionLoaderMixin"]
         _import_structure["ip_adapter"] = ["IPAdapterMixin"]
@@ -69,7 +68,6 @@ def text_encoder_attn_modules(text_encoder):
 
 if TYPE_CHECKING or DIFFUSERS_SLOW_IMPORT:
     if is_torch_available():
-        from .single_file import FromOriginalControlnetMixin, FromOriginalVAEMixin
         from .unet import UNet2DConditionLoadersMixin
         from .utils import AttnProcsLayers