refactor(voxtral_tts): drop pass-through _cached_apply_hf_processor

After the vLLM 0.29 adaptation the override only returned
super()._cached_apply_hf_processor(inputs, timing_ctx). Delete it together
with the imports it alone used (MultiModalProcessingInfo, TimingContext).
The find-only _maybe_apply_prompt_updates override is unchanged.

Validation: ruff and pre-commit on the file; the module imports cleanly;
tests/model_executor/models/voxtral_tts passes (62 tests).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MpXe2LeRrUQGjZfKFaocMZ
Signed-off-by: tzhouam <tzhouam@connect.ust.hk>

vllm_omni/model_executor/models/voxtral_tts/voxtral_tts_audio_generation.py

@@ -48,11 +48,9 @@ from vllm.multimodal.parse import AudioProcessorItems, MultiModalDataItems, Mult
 from vllm.multimodal.processing import BaseDummyInputsBuilder, BaseMultiModalProcessor
 from vllm.multimodal.processing.processor import (
     BaseProcessingInfo,
-    MultiModalProcessingInfo,
     ProcessorInputs,
     PromptReplacement,
     PromptUpdate,
-    TimingContext,
 )
 from vllm.sequence import IntermediateTensors
 from vllm.tokenizers import cached_tokenizer_from_config
@@ -899,13 +897,6 @@ class VoxtralTTSMultiModalProcessor(BaseMultiModalProcessor[VoxtralTTSProcessing
         )
         return mm_processed_data
 
-    def _cached_apply_hf_processor(
-        self,
-        inputs: ProcessorInputs,
-        timing_ctx: TimingContext,
-    ) -> MultiModalProcessingInfo:
-        return super()._cached_apply_hf_processor(inputs, timing_ctx)
-
     def _maybe_apply_prompt_updates(
         self,
         mm_items: MultiModalDataItems,