Ruby bindings (via Rust/magnus) for XXH3 — the modern XXH family from Yann Collet. Exposes both the 64-bit (XXH3_64bits) and the 128-bit (XXH3_128bits) variants through a Digest::Base-compatible API. Backed by the pure-Rust `xxhash-rust` crate, so there's no system-library runtime dependency.