Fix some test about enable_partial_send_recv(True)+sequence_parallel(True)

[xuxinyi389]

修复单测。enable_partial_send_recv=True + sequence_parallel=True 组合有问题——每一次 PP stage 间的 P2P 通信都在损坏数据。

[codecov-commenter]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@381425a). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
src/paddlefleet/models/gpt/gpt_model.py	50.00%	0 Missing and 1 partial ⚠️

❌ Your patch status has failed because the patch coverage (50.00%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop     #590   +/-   ##
==========================================
  Coverage           ?   50.00%           
==========================================
  Files              ?        1           
  Lines              ?        2           
  Branches           ?        1           
==========================================
  Hits               ?        1           
  Misses             ?        0           
  Partials           ?        1           

Flag	Coverage Δ
coverage_combine	50.00% <50.00%> (?)

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Files with missing lines	Coverage Δ
src/paddlefleet/models/gpt/gpt_model.py	50.00% <50.00%> (ø)

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