fix: RTL languages display incorrectly with soft line break(#7153)

[asjqkkkk]

To fix #7153

Before the fix:

RTL_before.mp4

After the fix:

RTL_after.mp4

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.

Project coverage is 71.99%. Comparing base (2a03498) to head (aeec716).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...rvice/ime/delta_input_on_non_text_update_impl.dart	0.00%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1025      +/-   ##
==========================================
- Coverage   72.00%   71.99%   -0.01%     
==========================================
  Files         319      319              
  Lines       15342    15360      +18     
==========================================
+ Hits        11047    11059      +12     
- Misses       4295     4301       +6     

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