fs: Fix RealFs::open_handle implementation for directories on windows (#40639)

Release Notes:

- Fixed worktree names not updating when renaming the root folder on
windows

crates/fs/src/fs.rs

@@ -558,7 +558,14 @@ impl Fs for RealFs {
     }
 
     async fn open_handle(&self, path: &Path) -> Result<Arc<dyn FileHandle>> {
-        Ok(Arc::new(std::fs::File::open(path)?))
+        let mut options = std::fs::OpenOptions::new();
+        options.read(true);
+        #[cfg(windows)]
+        {
+            use std::os::windows::fs::OpenOptionsExt;
+            options.custom_flags(windows::Win32::Storage::FileSystem::FILE_FLAG_BACKUP_SEMANTICS.0);
+        }
+        Ok(Arc::new(options.open(path)?))
     }
 
     async fn load(&self, path: &Path) -> Result<String> {

crates/worktree/src/worktree.rs

@@ -236,7 +236,7 @@ pub struct LocalSnapshot {
     /// All of the git repositories in the worktree, indexed by the project entry
     /// id of their parent directory.
     git_repositories: TreeMap<ProjectEntryId, LocalRepositoryEntry>,
-    /// The file handle of the worktree root. `None` if the worktree is a directory.
+    /// The file handle of the worktree root
     /// (so we can find it after it's been moved)
     root_file_handle: Option<Arc<dyn fs::FileHandle>>,
     executor: BackgroundExecutor,
@@ -3830,7 +3830,7 @@ impl BackgroundScanner {
                         .unbounded_send(ScanState::RootUpdated { new_path })
                         .ok();
                 } else {
-                    log::warn!("root path could not be canonicalized: {}", err);
+                    log::warn!("root path could not be canonicalized: {:#}", err);
                 }
                 return;
             }