[Bugfix] Fix Qwen2.5-omni/Qwen3-omni mm_processor cache for audio_in_video request

[Isotr0py]

Purpose

• Following PR for Support online use_audio_in_video #36319
• Actually, Qwen2.5-Omni and Qwen3-Omni processor's apply_prompt_updates is incorrect for audio_in_video=True with cache. Then second requests in multi-turn requests will fail, because it will fall to use_audio_in_video=False code path:

(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/renderers/base.py", line 715, in process_for_engine
(APIServer pid=820051)     engine_prompt = self._process_singleton(prompt)
(APIServer pid=820051)                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/renderers/base.py", line 691, in _process_singleton
(APIServer pid=820051)     return self._process_tokens(prompt)  # type: ignore[arg-type]
(APIServer pid=820051)            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/renderers/base.py", line 636, in _process_tokens
(APIServer pid=820051)     inputs = self._process_multimodal(
(APIServer pid=820051)              ^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/renderers/base.py", line 622, in _process_multimodal
(APIServer pid=820051)     mm_inputs = mm_processor.apply(mm_processor_inputs, mm_timing_ctx)
(APIServer pid=820051)                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/multimodal/processing/processor.py", line 1663, in apply
(APIServer pid=820051)     prompt_ids, mm_placeholders = self._maybe_apply_prompt_updates(
(APIServer pid=820051)                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/model_executor/models/qwen2_5_omni_thinker.py", line 646, in _maybe_apply_prompt_updates
(APIServer pid=820051)     prompt_ids, mm_placeholders = self._apply_prompt_updates(
(APIServer pid=820051)                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051)   File "/home/mozf/develop-projects/vllm/vllm/multimodal/processing/processor.py", line 1539, in _apply_prompt_updates
(APIServer pid=820051)     assert update_idx is not None, (
(APIServer pid=820051)            ^^^^^^^^^^^^^^^^^^^^^^
(APIServer pid=820051) AssertionError: Failed to apply prompt replacement for mm_items['audio'][0]

• In Support online use_audio_in_video #36319, we bypass mm processor cache for audio_in_video=True through override _cached_apply_hf_processor, because mm_cache will cause request failed when request hit.
• This PR corrects use_audio_in_video detection when mm processor cache is hit.

Test Plan

pytest -s -v tests/entrypoints/openai/test_video.py -k test_online_audio_in_video

Test Result

Tests should pass.

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• The test plan, such as providing test command.
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[gemini-code-assist]

Code Review

This pull request addresses a bug in the Qwen2.5-Omni and Qwen3-Omni models related to the mm_processor cache when audio_in_video=True. The fix involves correcting the use_audio_in_video detection when the mm processor cache is hit. The changes include modifications to qwen2_5_omni_thinker.py and qwen3_omni_moe_thinker.py to handle the cache logic correctly. I have identified a high severity issue in qwen2_5_omni_thinker.py related to the removal of unused imports, which could potentially break existing code if those imports were being used elsewhere.

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vllm/model_executor/models/qwen2_5_omni_thinker.py (83-84)

high: Removing ProcessorInputs and TimingContext imports might break other parts of the code if they are used elsewhere. It's better to ensure that these imports are not used anywhere else before removing them.

from vllm.multimodal.processing import (
    BaseDummyInputsBuilder,
    ProcessorInputs,
    TimingContext,
)

[DarkLight1337]

Can you add a regression test?

[DarkLight1337]

Suggested change

	if any([item is None for item in mm_kwargs["video"]]):
	if any(item is None for item in mm_kwargs["video"]):

Avoid repeated iteration (same below)