Windows: Fix canonicalize return UNC path (#11083)
In Windows platform, using notify to watch file events.
1. in [notify windows
implement](https://github.com/notify-rs/notify/blob/3df0f65152c8585cfb29d231c880b86b9164dcfd/notify/src/windows.rs#L344),
we get the full file path, just with `path.join(file_path)`.
2. In [zed worktree
start_backgroud_scan_tasks](https://github.com/zed-industries/zed/blob/d2569afe662be93c926eed1aeb2b17d050ba90b0/crates/worktree/src/worktree.rs#L679),
`abs_path` is not unc path, so we get all file events with not unc path.
3. but in [zed worktree
process_event](https://github.com/zed-industries/zed/blob/d2569afe662be93c926eed1aeb2b17d050ba90b0/crates/worktree/src/worktree.rs#L3619),
we `strip_prefix` unc path all times, it will always print annoy error.
@mikayla-maki I can't reopen pre closed pr #10501 .
Release Notes:
- N/A
CharlesChen0823
843d299d9a