For macOS, the Standalone Distribution uses separate aarch64 and x86_64
binaries, but TeX Live uses a single universal binary. For those, I'm
installing the binaries from the Standalone Distribution as normal, and
then I'm directly copying the x86_64 binary into x86_64-darwinlegacy,
and I'm merging the x86_64 and aarch64 binaries into a single universal
binary using llvm-lipo.