Option to disable font ligatures

### Problem

I'm using a font that has support for ligatures. However, I highly dislike working with them. In my regular IDE I have them disabled, but Code doesn't seem to have support for that.

### Proposal

Add a toggle to disable ligatures instead of enforcing them. This would be under `Preferences/Interface/Font` with the rest of the font-related settings.

### Prior Art (Optional)

_No response_

首先找到 Preferences/Interface/Font 设置以及编辑器当前的字体或连字配置。当该区域提供禁用连字的切换选项，并且编辑器遵循所选设置时，这项工作就完成了。

由索引模型根据 Issue 内容生成。