Summarized Changelog:

• Upgrade embedded tools including setuptools, pip, and wheel
• Fix unpacking dictionary items in PythonInfo.install_path
• Plugins now use 'selectable' entry points
• Use the better maintained platformdirs instead of appdirs
• Built in discovery class is always preferred over plugin supplied classes
• The builtin discovery takes now a --try-first-with argument and is first attempted as valid interpreters

Full version history available here.

Depends on D11690 and D11689 and D11688

Built python-tox against this version, and tested with tox.