Turbopack: Watch the root and every parent directory in non-recursive mode (#82129)
This only impacts the non-recursive codepath.
The notify-rs docs explain that you need to watch every parent of the file/directory you care about: https://docs.rs/notify/latest/notify/#parent-folder-deletion
This reduces the missing invalidations on Linux detected by my fuzzer, but does not eliminate them:
```
rm -rf /tmp/fuzz && cargo run --release -p turbo-tasks-fuzz -- fs-watcher --fs-root /tmp/fuzz
```