不支持链接目录

### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Diagnostics/Syntax Checking

### Expected Behaviour

我发现 不支持链接目录 虽然可以设置 workspace:Library 解决，但是会出现重复定义的字段提示

### Actual Behaviour

我发现 不支持链接目录 虽然可以设置 workspace:Library 解决，但是会出现重复定义的字段提示

### Reproduction steps

1. Go to '...'
2. Click '...'
3. See error '...'

### Additional Notes

_No response_

### Log File

_No response_

Reproduce the linked-directory diagnostic issue in the Visual Studio Code extension on Windows, using the reported workspace:Library workaround as a comparison. Trace how linked directories and duplicate-definition diagnostics are handled, and consider the issue resolved when linked directories work without introducing duplicate field warnings.

Written by the indexing model from the issue text.