[WIP] NNX in logits check, workaround

[hengtaoguo]

Description

Demo only, DO NOT merge.

It loads the full NNX ckpt using orbax API, unwrap the "base/value", and then apply the correct mesh to the params.

Tests

Please describe how you tested this change, and include any instructions and/or
commands to reproduce.

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 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/maxtext/utils/model_creation_utils.py	0.00%	8 Missing ⚠️

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