fix(Tabs): incorrect change event in some cases

[chenjiahan]

No description provided.

[github-actions]

🎊 PR Preview 0cc11a4 has been successfully built and deployed to https://youzan-vant-preview-pr-7461.surge.sh

🕐 Build time: 96.144s

_{🤖 By surge-preview}

[codecov-io]

Codecov Report

Merging #7461 into 2.x will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              2.x    #7461      +/-   ##
==========================================
+ Coverage   90.62%   90.65%   +0.02%     
==========================================
  Files         179      179              
  Lines        4886     4890       +4     
  Branches      296      296              
==========================================
+ Hits         4428     4433       +5     
+ Misses        420      419       -1     
  Partials       38       38              

Impacted Files	Coverage Δ
src/tabs/index.js	82.75% <100.00%> (+1.50%)	⬆️

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