[macOS, CI] Update dependencies, don't use lz4 from Homebrew

Also, enable double precision support for Bullet.

• https://github.com/OpenMW/openmw-deps-mac/pull/51
• https://github.com/OpenMW/openmw-deps-mac/pull/56
• https://github.com/OpenMW/openmw-deps-mac/pull/57

Supersedes #395 (closed).