CI doesn't support Apple Silicon

[jmchapman]

All macs released in the last three years are ARM based.

CI doesn't currently support them properly.

This will waste developer time (as they will either need to use emulated code or spend more time building locally, especially on the first run which may take hours if it includes building ghc) and also may lead to issues not being uncovered internally leading to a bad user experience when they are uncovered by the community or they are unable to install the development environment.