fix: remove Windows directory symlinks recursively

[a-rookie-of-C-language]

close #84

Summary

• Fix rm -rf on Windows directory symlinks (SYMLINKD).
• Avoid treating directory symlinks as regular files during recursive removal.
• Remove the link itself with the directory removal path instead of calling remove_file().
• Avoid counting directory symlink targets recursively for progress accounting.

Validation

• cargo check --manifest-path deps\coreutils\Cargo.toml -p uu_rm
• cargo test --manifest-path deps\coreutils\Cargo.toml --features rm --test tests test_recursive_symlink_dir_removes_link_not_target