Remove M1 Mac warning for one-line installation

What does this Merge Request do and why?

This MR removes a note about one-line installation not being compatible with M1 MacBooks.

Today I've successfully installed GDK using the one-line installation on my M1 Max MacBook Pro.

Merge Request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise Issue to follow-up.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.