fix: backspace on empty line doesn’t return to previous list item

[LIlGG]

What type of PR is this?

/kind bug
/area editor
/milestone 2.19.x

What this PR does / why we need it:

修复默认编辑器中，当在列表的下一空白行使用退格键时，会导致无法回退至列表项中的问题。

How to test it?

1. 在编辑器中增加一个列表项。
2. 按两次回车跳出列表编辑器。
3. 按退格键。

查看退格键是否按一次就可以回到列表项，并且再次按时执行列表项的删除。

Which issue(s) this PR fixes:

Fixes #6263

Does this PR introduce a user-facing change?

解决默认编辑器中在空白行中按退格键无法回退到列表项中的问题

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.15%. Comparing base (bc10336) to head (5d8d91b).
Report is 107 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6445      +/-   ##
============================================
+ Coverage     54.51%   58.15%   +3.64%     
- Complexity     3523     3769     +246     
============================================
  Files           646      651       +5     
  Lines         21862    22106     +244     
  Branches       1528     1555      +27     
============================================
+ Hits          11917    12855     +938     
+ Misses         9328     8628     -700     
- Partials        617      623       +6     

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[guqing]

/lgtm

[ruibaby]

/lgtm

[f2c-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ruibaby

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