Fix code quality issue at github head

[NuojCheng]

Description

Scheduled tests is broken at github head due to code quality failure, see here. This PR should fix code quality bug to unblock scheduled tests.

FIXES: b/534393522

Tests

CI

Checklist

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• I have performed a self-review of my code. For an optional AI review, add the gemini-review label.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed, including adding new documentation pages to the relevant Table of Contents (toctree directive) as explained in our documentation.

[codecov]

Codecov Report

❌ Patch coverage is 27.58621% with 63 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/maxtext/input_pipeline/protos/feature_pb2.py	6.66%	28 Missing ⚠️
src/maxtext/multimodal/processor_qwen3_omni.py	0.00%	10 Missing ⚠️
src/maxtext/input_pipeline/protos/example_pb2.py	25.00%	6 Missing ⚠️
...xtext/checkpoint_conversion/utils/param_mapping.py	33.33%	4 Missing ⚠️
src/maxtext/input_pipeline/input_pipeline_utils.py	60.00%	2 Missing ⚠️
...xtext/kernels/attention/splash_attention_kernel.py	0.00%	2 Missing ⚠️
src/maxtext/layers/nnx_wrappers.py	0.00%	2 Missing ⚠️
src/maxtext/multimodal/processor.py	0.00%	2 Missing ⚠️
src/maxtext/multimodal/utils.py	0.00%	2 Missing ⚠️
...t/integration/vllm/maxtext_vllm_adapter/adapter.py	0.00%	1 Missing ⚠️
... and 4 more

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