update rope_max_timescale to 1M for qwen3-30b-a3b-base to match HF

[JamesDeng42]

Description

This PR updates the rope_max_timescale for the qwen3-30b-a3b-base model configuration from 10,000,000 to 1,000,000.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[github-actions]

🤖 Hi @gagika, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.

[github-actions]

## 📋 Review Summary

This Pull Request correctly updates the rope_max_timescale (and its Hugging Face counterpart rope_theta) for the qwen3-30b-a3b-base model to align with the Hugging Face configuration. The change ensures consistency between the MaxText model configuration and the checkpoint conversion utilities.

🔍 General Feedback

• The changes are focused and follow the established patterns in the codebase for model configuration and HF mapping.
• I noticed that while the model has been added to hf_model_configs.py and param_mapping.py, it is currently missing from src/maxtext/checkpoint_conversion/utils/hf_shape.py. This omission will likely cause the to_huggingface conversion script to fail for this specific model variant. I have added an inline comment suggesting this addition.
• Overall, the PR is high quality and addresses the requirement of matching HF configurations.

[gagika]

can you have qwen3_30b_a3b_thinking_2507_config inherit from qwen3_30b_a3b_base_config and just override rope_theta=1000000?

also @parambole could you review qwen3-30b base model config change to match hf?