Revert "[MM][CG] Support ViT full CUDA graph for Ernie-4.5-VL image inference" (#45254)

[vllm-agent]

Reverts #45254 — [MM][CG] Support ViT full CUDA graph for Ernie-4.5-VL image inference

Why: the new Ernie4_5_VLMoeForConditionalGeneration.postprocess_encoder_output crashes on its own test case.

File "vllm/model_executor/models/ernie45_vl.py", line 1734, in postprocess_encoder_output
    grid_thw = batch_mm_kwargs["image_grid_thw"].to(output.device)
AttributeError: 'dict' object has no attribute 'device'

output is a dict at this call site, so encoder CUDA-graph replay fails for Ernie-4.5-VL immediately.

• Failing job: Multi-Modal Models (Extended Generation 1) — tests/models/multimodal/generation/test_vit_cudagraph.py::test_vit_cudagraph_image[ernie45_vl]
• Failures linked to this PR: 1
• Build: https://buildkite.com/vllm/ci/builds/82629 (commit c0202c5)
• The ernie45_vl case was added by this same PR, so the job was green before it merged.

The revert applied cleanly with no conflicts. Happy to close this in favour of a one-line fix-forward.

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[mergify]

Documentation preview: https://vllm--51263.org.readthedocs.build/en/51263/

[qyYue1389]

Thanks for catching this

It's a semantic merge conflict, not a bug in the original logic. The SupportsEncoderCudaGraph.postprocess_encoder_output signature changed to a multi-path form — it now receives outputs: dict[str, torch.Tensor] keyed by encoder path, and the caller in encoder_cudagraph.py passes graph_outputs (a dict). #45254 was written and CI-green against the older single-tensor signature; the two landed close together, so each was green independently but the combination broke Ernie's override:

grid_thw = batch_mm_kwargs["image_grid_thw"].to(output.device)
AttributeError: 'dict' object has no attribute 'device'

I've opened a one-line fix in #51461 — it just updates Ernie's override to the current signature and pulls out the single "default" path output:

def postprocess_encoder_output(self, outputs: dict[str, torch.Tensor], ...):
    output = outputs["default"]
    grid_thw = batch_mm_kwargs["image_grid_thw"].to(output.device)
    ...

Verified locally with the exact case from build 82629:
pytest tests/models/multimodal/generation/test_vit_cudagraph.py::test_vit_cudagraph_image[ernie45_vl]

Could we merge #51461 and close this revert PR? Thank you!

[khluu]

superseded by #51461