fix(input): fix group style problem

[flsion]

Types of changes

• New feature
• Bug fix
• Enhancement
• Component style change
• Typescript definition change
• Documentation change
• Coding style change
• Refactoring
• Test cases
• Continuous integration
• Breaking change
• Others

Background and context

Solution

How is the change tested?

Changelog

Component	Changelog(CN)	Changelog(EN)	Related issues
input	修复 Input.Group 在线性主题下边框重叠的问题	Fix the problem of overlapping borders of Input.Group under linear theme

Checklist:

• Test suite passes (npm run test)
• Provide changelog for relevant changes (e.g. bug fixes and new features) if applicable.
• Changes are submitted to the appropriate branch (e.g. features should be submitted to feature branch and others
  should be submitted to main branch)

Other information