Let's say you run this:

```
cd ~/proj-a
zed ~/proj-b
```

The `zed` process will execute with `current_dir() = ~/proj-a`, but a
`worktree_root_path() = ~/proj-b`. The old detection was then checking
if the Yarn SDK was installed in `proj-a` to decide whether to set the
tsdk value or not. This was incorrect, as we should instead check for
the SDK presence inside `proj-b`.

Release Notes:

- Fixed the Yarn SDK detection when the Zed pwd is different from the
opened folder.