Fix layerwise GaLore optimizer hard to converge with warmup scheduler

[hiyouga]

What does this PR do?

Fixes #30371 , a detailed explanation has been provided in the issue.

After this fix, the loss can converge similarly as the non-warmup scheduler

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline,
  Pull Request section?
• Was this discussed/approved via a Github issue or the forum? Please add a link
  to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@muellerzr and @younesbelkada

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[younesbelkada]

Thank you very much for the prompt fix !

[amyeroberts]

Thanks for digging into this and fixing!