Support for ARM-based Big Sur

[ShadowJonathan]

According to packaging.tags and macos wheel tagging, with the introduction of MacOS 11.0, there's a new architecture to target; arm64

While x86_64-based MacOS 11+ targets will be able to support 10.*, with ARM, it obviously wouldn't.

I couldn't find any issues or notes pointing out explicit support for this target (the compatibility matrix lists MacOS x86_64 only, for example), so i'm making this one here to track development/support/comments for it.

[Czaki]

The discussion started in #473. It partially depends on changes in wheel package. Its fixed release was published, so the work could slowly start.

[joerick]

Closed as dupe of #473

[ShadowJonathan]

Closed as dupe of #473

Thanks, I didn't definitively know if that other discussion had covered this.