Dumac: Significant Performance Improvements in a macOS Disk Usage Tool

Dumac, a macOS disk usage utility faster than `du -sh`, leverages the macOS-specific `getattrlistbulk` syscall. After incorporating community feedback, the author boosted performance by ~33% by switching from Tokio to Rayon for improved parallelism and optimizing inode hash-set sharding. Addressing inode contention through a refined sharding strategy yielded further speed gains.