Onboard to cibuildwheel and improve macOS build

[snnn]

Description:

This PR adds python packages for PyPy LInux x86_64, CPython 3.6-3.9 macOS ARM, CPython 3.6-3.9 CentOS 8.

Add Linux/Mac ARM64 binaries to Microsoft.ML.OnnxRuntime nuget package.

cibuildwheel is a tool to help build python packages across Mac, Linux, Windows, on multiple versions of Python.

Add the ability of cross compiling for another CPU ARCH on macOS without building protoc separately. For example, build ORT arm64 on a x86_64 macOS or vice versa. And add the ability to generate universal2 binaries for macOS. It can be set through CMAKE_OSX_ARCHITECTURES.

And remove onnxruntime_CROSS_COMPILING cmake option because it is very confusing. When you an iOS app on x86_64, is it considered as cross compiling or not? No, it's not. But building for Windows ARM is, and building for macOS ARM is not. I believe it will confuse all the people. Therefore, we should not expose such a configuration.

And remove Linux-iOS cross-compiling based on the TODO comment in build.py. "The cross compiling on Linux is not officially supported by Apple and is already broken with the latest codebase, so it should be removed"

Motivation and Context

• Why is this change required? What problem does it solve?
• If it fixes an open issue, please link to the issue here.

#8420 #6633 #6573

[snnn]

[snnn]

I'm splitting it to smaller pieces.

[mbalesni]

@chilo-ms it seems you are the last reviewer left to merge this. Is there anything in the way?

[stale]

This issue has been automatically marked as stale due to inactivity and will be closed in 7 days if no further activity occurs. If further support is needed, please provide an update and/or more details.