Re-enable once pure_nnx config issue for DeepseekV4

[dipakg-lang]

Description

Start with a short description of what the PR does and how this is a change from
the past.

https://b.corp.google.com/issues/544531325

If the change fixes a bug or a Github issue, please include a link, e.g.,:
FIXES: b/544531325

Notice 1: Once all tests pass, the "pull ready" label will automatically be assigned.
This label is used for administrative purposes. Please do not add it manually.

Notice 2: For external contributions, our settings currently require an approval from a MaxText maintainer to trigger CI tests.

Tests

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

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• 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.

[gemini-code-assist]

Code Review

This pull request re-enables the deepseek4-284b model integration test by setting the pure_nnx flag for this model and updating the _DEEPSEEK4_MLP_SCANNED dictionary. Feedback suggests consolidating _DEEPSEEK4_MLP_SCANNED and _DEEPSEEK4_MLP since they are now identical, and using a set instead of a direct string comparison for checking is_pure_nnx to improve extensibility.

[gemini-code-assist]

With the removal of "bias": None from "gate", _DEEPSEEK4_MLP_SCANNED is now completely identical to _DEEPSEEK4_MLP (defined on line 249). To improve maintainability and reduce code duplication, consider consolidating them in a future refactor (e.g., by pointing _DEEPSEEK4_MLP_SCANNED = _DEEPSEEK4_MLP or removing one of them entirely).

[gemini-code-assist]

Hardcoding the model name check model_name == "deepseek4-284b" is fragile and less extensible if other models are migrated to pure_nnx in the future. Using a set of models or a prefix check makes it cleaner and easier to maintain.

Suggested change

	is_pure_nnx = model_name == "deepseek4-284b"
	actual_output = muon_utils.get_model_mdn(model_name, scan_layers=True, pure_nnx=is_pure_nnx)
	is_pure_nnx = model_name in {"deepseek4-284b"}
	actual_output = muon_utils.get_model_mdn(model_name, scan_layers=True, pure_nnx=is_pure_nnx)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!