let tunix see lr hyperparams for logging

[andytwigg]

Description

use optax hyperparam inject wrapper to let tunix see lr hyperparams for logging

Tests

ran and observed that tunix was logging LR correctly.

Checklist

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[codecov]

Codecov Report

❌ Patch coverage is 44.44444% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/maxtext/trainers/post_train/rl/utils_rl.py	44.44%	5 Missing ⚠️

📢 Thoughts on this report? Let us know!

[A9isha]

Thanks Andy!

[richjames0]

lgtm