Add aarch64-darwin nix support 🙏

[danielmain]

Why

Apple is already shipping only aarch64 machines since 2019, that is why a good a mount of developers work with an apple machine with a M1/M2 chip

What

Entering in the nix shell by calling nix develop I get the following error:

error: flake 'git+file:///Workspace/cardano/hydra' does not provide attribute 'devShells.aarch64-darwin.default', 'devShell.aarch64-darwin', 'packages.aarch64-darwin.default' or 'defaultPackage.aarch64-darwin'

[abailly]

I will get my new M2 machine in a couple weeks, then I will be forced to add support for ARM ;)

[ch1bo]

@danielmain can you test this branch #674? I don't have a suitable machine.

[Red3nzo]

This is honestly the reason I've been having a hard time considering Apple again, I mostly work with linux based containers & the lack of aarch64-darwin is nuts. Cardano itself doesn't seem to even have the cardano-node docker image compatible with aarch64-darwin

[pgrange]

Should be fixed by #674