fix: correct import path for load_model_dict_into_meta in conversion scripts (#12616)

The function load_model_dict_into_meta was moved from modeling_utils.py to
model_loading_utils.py but the imports in the conversion scripts were not
updated, causing ImportError when running these scripts.

This fixes the import in 6 conversion scripts:
- scripts/convert_sd3_to_diffusers.py
- scripts/convert_stable_cascade_lite.py
- scripts/convert_stable_cascade.py
- scripts/convert_stable_audio.py
- scripts/convert_sana_to_diffusers.py
- scripts/convert_sana_controlnet_to_diffusers.py

Fixes #12606

scripts/convert_sana_controlnet_to_diffusers.py

@@ -10,7 +10,7 @@ from accelerate import init_empty_weights
 from diffusers import (
     SanaControlNetModel,
 )
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.utils.import_utils import is_accelerate_available
 
 

scripts/convert_sana_to_diffusers.py

@@ -20,7 +20,7 @@ from diffusers import (
     SanaTransformer2DModel,
     SCMScheduler,
 )
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.utils.import_utils import is_accelerate_available
 
 

scripts/convert_sd3_to_diffusers.py

@@ -7,7 +7,7 @@ from accelerate import init_empty_weights
 
 from diffusers import AutoencoderKL, SD3Transformer2DModel
 from diffusers.loaders.single_file_utils import convert_ldm_vae_checkpoint
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.utils.import_utils import is_accelerate_available
 
 

scripts/convert_stable_audio.py

@@ -18,7 +18,7 @@ from diffusers import (
     StableAudioPipeline,
     StableAudioProjectionModel,
 )
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.utils import is_accelerate_available
 
 

scripts/convert_stable_cascade.py

@@ -20,7 +20,7 @@ from diffusers import (
 )
 from diffusers.loaders.single_file_utils import convert_stable_cascade_unet_single_file_to_diffusers
 from diffusers.models import StableCascadeUNet
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.pipelines.wuerstchen import PaellaVQModel
 from diffusers.utils import is_accelerate_available
 

scripts/convert_stable_cascade_lite.py

@@ -20,7 +20,7 @@ from diffusers import (
 )
 from diffusers.loaders.single_file_utils import convert_stable_cascade_unet_single_file_to_diffusers
 from diffusers.models import StableCascadeUNet
-from diffusers.models.modeling_utils import load_model_dict_into_meta
+from diffusers.models.model_loading_utils import load_model_dict_into_meta
 from diffusers.pipelines.wuerstchen import PaellaVQModel
 from diffusers.utils import is_accelerate_available