split-pane组件事件失效

官方demo链接测试split-pane组件，on-trigger-moving事件正常，但是clone代码后，安装完依赖，npm run dev跑测试时发现split-pane组件拖动边界线，发现on-trigger-moving不能触发，望测试修复

Start by comparing the official split-pane demo with the cloned project launched using npm run dev. Reproduce dragging the split-pane boundary and trace why the on-trigger-moving event is not fired locally. Done means the event is triggered during dragging as it is in the official demo, with a regression test if the existing test setup identifies a suitable location.

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