fix(animation): fix preprocessKeyframes

[Aarebecca]

• 修复 preprocessKeyframes 问题

当传入关键帧被全部过滤清空后，不会执行动画而是直接结束，如果是退场动画则会直接销毁该元素，此时如果有其他相关元素正在执行动画，会导致找不到该元素。

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• Fixed the preprocessKeyframes issue

When the incoming key frame is cleared by all filters, the animation is not executed but directly ended. If it is an exit animation, the element is directly destroyed. At this time, if other related elements are performing animation, the element cannot be found.

ISSUE: #5951