fix: back-top animation error

[li-jia-nan]

[中文版模板 / Chinese template]

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🔗 Related issue link

• close FloatButton-回到顶部dome逻辑写反了 #38769

💡 Background and solution

📝 Changelog

Language	Changelog
🇺🇸 English	fix: back-top animation error
🇨🇳 Chinese	fix: 修复回到顶部动画丢失的问题

☑️ Self-Check before Merge

⚠️ Please check all items below before requesting a reviewing. ⚠️

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
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[github-actions]

[codecov]

Codecov Report

Base: 100.00% // Head: 100.00% // No change to project coverage 👍

Coverage data is based on head (e15fcdd) compared to base (153f232).
Patch has no changes to coverable lines.

Additional details and impacted files

@@            Coverage Diff            @@
##            master    #38770   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          544       544           
  Lines         9350      9350           
  Branches      2649      2649           
=========================================
  Hits          9350      9350           

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[MadCcc]

换 dumi 之后还帮助发现 motion 的问题了