refactor: remove redundant try_flush invocations

[tisonkun]

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Refer to a related PR or issue link (optional)

This closes #2657.

What's changed and what's your intention?

TRIVIAL AS IS. Read the code and see #2657's description.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 85.05%. Comparing base (8779524) to head (b03206e).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3706      +/-   ##
==========================================
- Coverage   85.38%   85.05%   -0.33%     
==========================================
  Files         963      963              
  Lines      160719   160731      +12     
==========================================
- Hits       137231   136716     -515     
- Misses      23488    24015     +527