[Core] Move multimodal placeholder from chat utils to model definition (#20355)

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

vllm/model_executor/models/__init__.py

@@ -2,9 +2,9 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
 from .interfaces import (HasInnerState, SupportsLoRA, SupportsMultiModal,
-                         SupportsPP, SupportsV0Only, has_inner_state,
-                         supports_lora, supports_multimodal, supports_pp,
-                         supports_v0_only)
+                         SupportsPP, SupportsTranscription, SupportsV0Only,
+                         has_inner_state, supports_lora, supports_multimodal,
+                         supports_pp, supports_transcription, supports_v0_only)
 from .interfaces_base import (VllmModelForPooling, VllmModelForTextGeneration,
                               is_pooling_model, is_text_generation_model)
 from .registry import ModelRegistry
@@ -23,6 +23,8 @@ __all__ = [
     "supports_multimodal",
     "SupportsPP",
     "supports_pp",
+    "SupportsTranscription",
+    "supports_transcription",
     "SupportsV0Only",
     "supports_v0_only",
 ]