feature: use ABI3 for cp36+

[mayeut]

Summary

• OS: all
• Bug fix: no
• Type: wheels
• Fixes: fixes #2089 fixes #1954 closes #2021 closes #2040

Description

Use Limited API when building with CPython 3.6+ on Linux/macOS/Windows. This allows to use pre-built wheels in all future versions of CPython 3. Windows builds for CPython 3.6+ are moved from AppVeyor to GitHub Actions.

This PR is based on #2040 so it also adds a universal2 wheel for macOS and updates the build workflow to use the latest cibuildwheel as a GitHub Action. cibuildwheel configuration is now in its own file (as there's no pyproject.toml yet).

Diff of wheels produced:

+psutil-5.9.1-cp27-cp27m-macosx_10_9_x86_64.whl
 psutil-5.9.1-cp27-cp27m-manylinux2010_i686.whl
 psutil-5.9.1-cp27-cp27m-manylinux2010_x86_64.whl
 psutil-5.9.1-cp27-cp27m-win_amd64.whl
 psutil-5.9.1-cp27-cp27m-win32.whl
 psutil-5.9.1-cp27-cp27mu-manylinux2010_i686.whl
 psutil-5.9.1-cp27-cp27mu-manylinux2010_x86_64.whl
+psutil-5.9.1-cp35-cp35m-manylinux2010_i686.whl
+psutil-5.9.1-cp35-cp35m-manylinux2010_x86_64.whl
-psutil-5.9.1-cp36-cp36m-macosx_10_9_x86_64.whl
+psutil-5.9.1-cp36-abi3-macosx_10_9_x86_64.whl
-psutil-5.9.1-cp36-cp36m-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
+psutil-5.9.1-cp36-abi3-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
-psutil-5.9.1-cp36-cp36m-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
+psutil-5.9.1-cp36-abi3-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
-psutil-5.9.1-cp36-cp36m-win_amd64.whl
+psutil-5.9.1-cp36-abi3-win_amd64.whl
-psutil-5.9.1-cp36-cp36m-win32.whl
+psutil-5.9.1-cp36-abi3-win32.whl
-psutil-5.9.1-cp37-cp37m-macosx_10_9_x86_64.whl
-psutil-5.9.1-cp37-cp37m-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
-psutil-5.9.1-cp37-cp37m-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
-psutil-5.9.1-cp37-cp37m-win_amd64.whl
-psutil-5.9.1-cp37-cp37m-win32.whl
-psutil-5.9.1-cp38-cp38-macosx_10_9_x86_64.whl
+psutil-5.9.1-cp38-abi3-macosx_10_9_universal2.whl
-psutil-5.9.1-cp38-cp38-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
-psutil-5.9.1-cp38-cp38-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
-psutil-5.9.1-cp38-cp38-win_amd64.whl
-psutil-5.9.1-cp38-cp38-win32.whl
-psutil-5.9.1-cp39-cp39-macosx_10_9_x86_64.whl
-psutil-5.9.1-cp39-cp39-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
-psutil-5.9.1-cp39-cp39-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
-psutil-5.9.1-cp39-cp39-win_amd64.whl
-psutil-5.9.1-cp39-cp39-win32.whl
-psutil-5.9.1-cp310-cp310-macosx_10_9_x86_64.whl
-psutil-5.9.1-cp310-cp310-manylinux_2_12_i686.manylinux2010_i686.manylinux_2_17_i686.manylinux2014_i686.whl
-psutil-5.9.1-cp310-cp310-manylinux_2_12_x86_64.manylinux2010_x86_64.manylinux_2_17_x86_64.manylinux2014_x86_64.whl
-psutil-5.9.1-cp310-cp310-win_amd64.whl
-psutil-5.9.1-cp310-cp310-win32.whl