Fix saving adapter weights after disabling DSD

[acisseJZhong]

Context

What is the purpose of this PR? Is it to

• add a new feature
• fix a bug
• update tests and/or documentation
• other (please add here)

Please link to any issues this PR addresses.

Changelog

What are the changes made in this PR?
*

Test plan

Please make sure to do each of the following if applicable to your PR. If you're unsure about any one of these just ask and we will happily help. We also have a contributing page for some guidance on contributing.

• run pre-commit hooks and linters (make sure you've first installed via pre-commit install)
• add unit tests for any new functionality
• update docstrings for any new or updated methods or classes
• run unit tests via pytest tests
• run recipe tests via pytest tests -m integration_test
• manually run any new or modified recipes with sufficient proof of correctness
• include relevant commands and any other artifacts in this summary (pastes of loss curves, eval results, etc.)

UX

If your function changed a public API, please add a dummy example of what the user experience will look like when calling it.
Here is a docstring example
and a tutorial example

• I did not change any public API
• I have added an example to docs or docstrings

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/torchtune/2351

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❗ 1 Active SEVs

There are 1 currently active SEVs. If your PR is affected, please view them below:

• ROCM Infra failures during checkout of PyTorch

⏳ No Failures, 1 Pending

As of commit 8e8acff with merge base a226a58 ():
💚 Looks good so far! There are no failures yet. 💚

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[ebsmothers]

I think this should happen outside the for loop at the end

[acisseJZhong]

sry, my brain died at the end of day 😞

[ebsmothers]

Thanks for the fix! Once CI is green I think this is good to merge

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 66.86%. Comparing base (e6b9064) to head (8e8acff).
Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
torchtune/training/_distributed.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2351       +/-   ##
===========================================
+ Coverage   23.72%   66.86%   +43.14%     
===========================================
  Files         361      356        -5     
  Lines       21492    20943      -549     
===========================================
+ Hits         5098    14003     +8905     
+ Misses      16394     6940     -9454     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.