Update to minimum Python 3.9.
Drop support for x86_64 on macOS.
Use the clang compiler on the windows platform.
Move to RHEL 8 compatible manylinux_2_28.
Add .clang-format file to provide assist automatic formatting for new source code.
macOS is now a universal build for both arm64 and x86_64. Minimum deployment version is now 12.0.
Update copyright. Build for aarch64 linux.