ci: Switch Apple jobs to the Arm64 runner
Hi all,
This PR is to update the CI to use the Apple silicon runner. I've had to pin Meson and work around its cross-build detection because it isn't able to handle same-system, same-architecture builds properly (e.g. macOS Arm64 to iOS, or macOS x86-64 to iOS Simulator).
Fixes #41 (closed)