sysutils/rust-findutils: update to 0.10.0

Drop the LLVM dependency: onig is used without its bindgen feature, so
libclang was never needed. Set RUSTONIG_SYSTEM_LIBONIG so onig_sys links
the oniguruma from ports instead of compiling its bundled copy. Adds the
locate and updatedb utilities.

Changelog: https://github.com/uutils/findutils/releases/tag/0.10.0