【FlexCheckpoint】fix save hf bug

[xingmingyyj]

Before submitting

• Lint code. If there are lint issues, please format the code first.

# Install and register `pre-commit` in the project folder
pip install pre-commit && pre-commit install

# Process previous code files separately
pre-commit run --file XXXX.py

• Add test cases into tests folder. If there are codecov issues, please add tests cases first.

PR types

Bug fixes

PR changes

Others

Description

• 多机下只有单机存ckpt，部分卡调用barrier导致hang。
• max_shard_size默认设置为10GB，4机qwen3moe显存余量不足10GB

[paddle-bot]

Thanks for your contribution!

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[xingmingyyj]

/re-run all-failed

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@729d212). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
paddleformers/transformers/model_utils.py	0.00%	2 Missing ⚠️

❌ Your patch status has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop    #3030   +/-   ##
==========================================
  Coverage           ?   33.60%           
==========================================
  Files              ?      428           
  Lines              ?    69466           
  Branches           ?        0           
==========================================
  Hits               ?    23341           
  Misses             ?    46125           
  Partials           ?        0           

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