Add artifact for Apple Silicon

[ropoko]

The current mac-os artifact is only for x86_64, and it would be nice to have the arm64 version

[tpimh]

Definitely a good idea.

love2d/love#2008 (comment):

According to https://store.steampowered.com/hwsurvey/Steam-Hardware-Software-Survey-Welcome-to-Steam?platform=mac 70% of mac steam users have an arm64 system, so you might not want to leave that out - and your x64 library will fail to work on those systems anyway unless you strip out the arm64 part of love.app to make it use Rosetta x64 emulation.

[slime73]

I want to do this, but I'd like it to be a fat binary containing both arm64 and x64 (just like love and other native apps and libraries), which probably needs a bit more fiddling with the CI setup and maybe the CMake project than otherwise.

[slime73]

Done in 221bb84