ci: add macos builds

[jmg-duarte]

Description

As the title states.

Closes #563

Had to reformulate the way the jobs are done because the self-hosted runner doesn't require the setup rust toolchain step.

Deleted the following release to avoid confusion, so here's a print as proof

jmgd@athos ~/Downloads
▶ sha256sum mater-cli-*
e34b1b743226a9cb4826103a0933f3e205c29b4b77e4a060aba29108079716ce  mater-cli-linux-x64
563644f10efc26b85be509dc5a34289faa8aefc85649fe03eb4183cd716c0b60  mater-cli-macos-arm64
da43daac74412030baaa3b8ec3f0865bf6eb556dd07e729947d0975ea8a176d4  mater-cli-macos-x64
jmgd@athos ~/Downloads
▶ file mater-cli*
mater-cli-linux-x64:   ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=e582bd2e4984e768a8326505d7136a62e2e4eeee, for GNU/Linux 3.2.0, not stripped
mater-cli-macos-arm64: Mach-O 64-bit executable arm64
mater-cli-macos-x64:   Mach-O 64-bit executable x86_64

[jmg-duarte]

Converted to draft to avoid merging while we're releasing stuff.

[jmg-duarte]

Dropping automatic support since MacOS runners are so expensive