fix: explicitly set config instead of using changable default in tests

[MichaelScofield]

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fix #4126

What's changed and what's your intention?

fix the test failure in #4126

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR requires documentation updates.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.13%. Comparing base (587e99d) to head (f2fa4cd).
Report is 2 commits behind head on main.

❗ Current head f2fa4cd differs from pull request most recent head 48d5d1d

Please upload reports for the commit 48d5d1d to get more accurate results.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4132      +/-   ##
==========================================
- Coverage   85.46%   85.13%   -0.33%     
==========================================
  Files         994      994              
  Lines      174348   174348              
==========================================
- Hits       149005   148436     -569     
- Misses      25343    25912     +569     

[tisonkun]

Does this mean that the default value is improper and we should revisit them later? Or just the one for this scenario need tunning.

[evenyag]

LGTM

[evenyag]

Does this mean that the default value is improper and we should revisit them later?

No. These default options are auto-tunable. They depend on the total memory and cores of the host machine running the test. We can't assert the value of the default option with a fixed value in the example config file.