fix(Stepper): 修复blur事件触发异常

[weiyuc]

link issue: #8615

[codecov-commenter]

Codecov Report

Merging #8620 (7073e61) into dev (e9c2549) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##              dev    #8620   +/-   ##
=======================================
  Coverage   86.52%   86.53%           
=======================================
  Files         217      217           
  Lines        5426     5427    +1     
  Branches     1340     1340           
=======================================
+ Hits         4695     4696    +1     
  Misses        461      461           
  Partials      270      270           

Impacted Files	Coverage Δ
src/stepper/Stepper.tsx	94.91% <100.00%> (+0.04%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e9c2549...7073e61. Read the comment docs.

[chenjiahan]

👏👏👏