fix:unable to select workplace at the bottom

[fanghongtai]

Description

it is unable to select workplace at the bottom when I have many workplaces. after the fix,a scroll bar will appear when the maximum height is exceeded

Fixes # (issue)

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update, included: Dify Document
• Improvement, including but not limited to code refactoring, performance optimization, and UI/UX improvement
• Dependency upgrade

How Has This Been Tested?

before the fix:

after the fix: