.net 6.0以上 自定义 UITypeEditor的属性界面无法显示 (.NET 6.0 or above Custom UITypeEditor's properties interface can't be displayed)

### Type of issue

Typo

### Description

.net 8.0 自定义 UITypeEditor的属性界面无法显示；
把.net 8.0改成net48即可解决问题；
已经在配置预览设计器也无法解决当前问题；

Translation: .NET 8.0 custom UITypeEditor's properties interface cannot be displayed;
Changing .net 8.0 to net48 solves the problem;
Already configuring the preview designer does not solve the current problem;

### Page URL

https://learn.microsoft.com/zh-cn/dotnet/api/system.drawing.design.uitypeeditor?view=windowsdesktop-10.0

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Drawing.Design/UITypeEditor.xml

### Document Version Independent Id

728f4108-8f3a-83f1-7998-484e4f5f7156

### Platform Id

e2ceacf6-dae1-d0ba-3718-be9002d41ebd

### Article author

@dotnet-bot