refactor: change the number of queried attachments in the selector modal

[ruibaby]

What type of PR is this?

/area ui
/kind improvement
/milestone 2.18.x

What this PR does / why we need it:

修改附件选择组件的默认显示数量，以解决因为图片数量过多或者图片过大导致的卡顿问题。

Which issue(s) this PR fixes:

Ref #6352

Does this PR introduce a user-facing change?

修改附件选择组件的默认显示数量，以解决因为图片数量过多或者图片过大导致的卡顿问题。

[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 58.34%. Comparing base (bc10336) to head (2e8966f).
Report is 88 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #6402      +/-   ##
============================================
+ Coverage     54.51%   58.34%   +3.83%     
- Complexity     3523     3766     +243     
============================================
  Files           646      646              
  Lines         21862    21989     +127     
  Branches       1528     1546      +18     
============================================
+ Hits          11917    12829     +912     
+ Misses         9328     8538     -790     
- Partials        617      622       +5     

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[guqing]

/lgtm

[f2c-ci-robot]

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• ui/OWNERS [guqing]

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