fix: statistic countdown typings

[Lukinoh]

This is a ...

• New feature
• Bug fix
• Site / document update
• Component style update
• TypeScript definition update
• Refactoring
• Code style optimization
• Branch merge
• Other (about what?)

What's the background?

1. Describe the source of requirement.

Remove typings error in the console when using ant-design-vue in my project.

2. Resolve what problem.

There is some inconsistancy in the typings of statistic-counted definition file, and that produce the following error during type checking:

ant-design-vue/types/statistic/statistic-countdown"' has no default export.

3. Related issue link.

Should I create a separate issue ?

Self Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

[netlify]

Deploy preview for ant-desing-vue processing.

Building with commit d25e62e

https://app.netlify.com/sites/ant-desing-vue/deploys/5dbd82b438cbdb0008e9b2f2

[codecov]

Codecov Report

Merging #1375 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1375   +/-   ##
=======================================
  Coverage   87.89%   87.89%           
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  Files         156      156           
  Lines        5393     5393           
  Branches     1521     1521           
=======================================
  Hits         4740     4740           
  Misses        583      583           
  Partials       70       70

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[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.