I can't switch session from worktrees to local

### Short summary

I lost the option to switch from worktrees to local

### Affected version or release

1.1.9

### Installation context

_No response_

### What happened?

In latest Windows version 1.1.9, it removed the option for us to switch between local VS worktree. I want it back!
The worktree doesn't work for our projects as our repo has a lot of submodules. It's not convenient to checkcout a worktree. There's no way to build and test in a worktree. It's broken. Please bring the settings back.

### Steps to reproduce
**Before**:

**After**:

### Expected behavior
I can let Copilot just update my code in current branch, so I can build and test there.

### Additional context

_No response_

在 Windows 上使用版本 1.1.9 重现该问题，并比较 Before 和 After 截图。追踪用于在 worktrees 和当前本地分支之间进行选择的设置，然后验证切换选项可用，并且 Copilot 能够为使用子模块的项目更新当前分支。

由索引模型根据 Issue 内容生成。