fix(calendar): fix fullcalendar content 2px overflow

[Yangzhedi]

there is a 2px overflow in fullcalendar-content,

https://ant.design/components/calendar-cn/

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[codecov]

Codecov Report

Merging #10808 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #10808   +/-   ##
=======================================
  Coverage   91.57%   91.57%           
=======================================
  Files         194      194           
  Lines        4762     4762           
  Branches     1328     1328           
=======================================
  Hits         4361     4361           
  Misses        397      397           
  Partials        4        4

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