[Misc] Clean up type annotation for SupportsMultiModal (#14794)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/model_executor/models/idefics3.py

@@ -49,7 +49,7 @@ from vllm.sequence import IntermediateTensors
 from .idefics2_vision_model import (
     Idefics2VisionTransformer as Idefics3VisionTransformer)
 # yapf: enable
-from .interfaces import SupportsLoRA, SupportsMultiModal
+from .interfaces import MultiModalEmbeddings, SupportsLoRA, SupportsMultiModal
 from .llama import LlamaModel
 from .utils import (AutoWeightsLoader, flatten_bn, maybe_prefix,
                     merge_multimodal_embeddings)
@@ -617,8 +617,7 @@ class Idefics3ForConditionalGeneration(nn.Module, SupportsMultiModal,
         self.sampler = get_sampler()
 
     def get_multimodal_embeddings(
-        self, **kwargs
-    ) -> Union[list[torch.Tensor], torch.Tensor, tuple[torch.Tensor, ...]]:
+            self, **kwargs: object) -> Optional[MultiModalEmbeddings]:
         image_input = self.model._parse_and_validate_image_input(**kwargs)
         if image_input is None:
             return None
@@ -628,7 +627,7 @@ class Idefics3ForConditionalGeneration(nn.Module, SupportsMultiModal,
     def get_input_embeddings(
         self,
         input_ids: torch.Tensor,
-        multimodal_embeddings: Optional[NestedTensors] = None,
+        multimodal_embeddings: Optional[MultiModalEmbeddings] = None,
     ) -> torch.Tensor:
         inputs_embeds = self.model.get_input_embeddings(input_ids)
         if multimodal_embeddings is not None: