fix(scanner): use individual store for loadConfigItemList

[noahziheng]

scanner/utils 中的 loadConfigItemList 方法用于在扫描每个 Ref 时加载其内部的配置，为了保证函数类型配置工作正常，此前复用了 app，但此前仅在扫描任务完全结束时清理了一次 ConfigStore，所以可能在某些 ref 中拿到被不正常合并后的配置，造成加载异常。

本 PR 调整项包括：

• loadConfigItemList 调整实现
  • 通过在 async 过程中替换 configStore 指向，确保每次调用该方法时使用一干净的 Store，调用结束前还原
• 移除已无必要的清理逻辑，减少误解
• 移除已无调用的 getAllConfig 方法，减少误解

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.01 ⚠️

Comparison is base (4688317) 91.72% compared to head (7cce44b) 91.71%.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master     #248      +/-   ##
==========================================
- Coverage   91.72%   91.71%   -0.01%     
==========================================
  Files          49       49              
  Lines        1196     1195       -1     
  Branches      214      212       -2     
==========================================
- Hits         1097     1096       -1     
  Misses         99       99              

Impacted Files	Coverage Δ
src/configuration/index.ts	70.58% <ø> (-3.10%)	⬇️
src/scanner/task.ts	95.38% <ø> (-0.04%)	⬇️
src/scanner/utils.ts	100.00% <100.00%> (ø)

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