Make the Yarn SDK path relative to the worktree (#40062)
Maël Nison
created
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.