Update TFDS MLPerf data input pipeline

[RissyRan]

Description

Enable the dataset loading for MLPerf 6.0 DeepSeek V3.

Tests

Expect tests are green.

Local tests:

• load new dataset: link

dataset_path=gs://mlperf-6-submission/tfds \
dataset_name='c4/en:3.0.5' \
eval_dataset_name='c4/en:3.0.5' \

• load old dataset: link

dataset_path=gs://max-datasets-rogue \
dataset_name='c4/en:3.0.7' \
eval_dataset_name='c4/en:3.0.9' \

Checklist

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• 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 0% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...t/input_pipeline/tfds_data_processing_c4_mlperf.py	0.00%	15 Missing ⚠️
src/maxtext/input_pipeline/input_pipeline_utils.py	0.00%	4 Missing ⚠️

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[shuningjin]

Thanks, LGTM! Left some minor comments. The gpu test has been fixed at head; please sync.

[shuningjin]

config.dataset_name -> config.eval_dataset_name

[shuningjin]

nit: typo "eval_spit" -> "eval_split", there are four such instances inside function make_c4_mlperf_eval_iterator