Automatically choose the correct architecture

[nex3]

Currently, this action always defaults to installing the x64 Dart binaries, even when running on architectures that aren't compatible with x64 (such as MacOS ARM). It would be nice if it instead defaulted to checking the current architecture and installing the matching binary.

[nex3]

It looks like this is still an issue, at least for Mac OS ARM machines: https://github.com/sass/dart-sass/actions/runs/4388953095/jobs/7686128912