fix(countdown): emit paused

[eiinu]

这个 PR 做了什么? (简要描述所做更改)

这个 PR 是什么类型? (至少选择一个)

• feat: 新特性提交
• fix: bug 修复
• docs: 文档改进
• style: 组件样式/交互改进
• type: 类型定义更新
• perf: 性能、包体积优化
• refactor: 代码重构、代码风格优化
• test: 测试用例
• chore(deps): 依赖升级
• chore(demo): 演示代码改进
• chore(locale): 国际化改进
• chore: 其他改动（是关于什么的改动？）

这个 PR 涉及以下平台:

• NutUI H5 @nutui/nutui
• NutUI Taro @nutui/nutui-taro

这个 PR 是否已自测:

• 自测 Vite 脚手架使用 测试仓库
• 自测 Taro 脚手架使用小程序 & Taro-H5 测试仓库

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.00%. Comparing base (0467755) to head (27cef5b).

Additional details and impacted files

@@            Coverage Diff             @@
##               v4    #3062      +/-   ##
==========================================
+ Coverage   83.96%   84.00%   +0.04%     
==========================================
  Files         223      223              
  Lines       23039    23039              
  Branches     2480     2483       +3     
==========================================
+ Hits        19344    19354      +10     
+ Misses       3677     3667      -10     
  Partials       18       18              

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