py-flit_core py-flit: updated to 3.8.0

Version 3.8

A project name containing hyphens is now automatically translated to use underscores for the import name
New option flit install --only-deps to install the dependencies of the package, but not the package itself.
Add support for recursive globbing (**) in sdist includes and excludes
Python窶冱 bytecode cache files (__pycache__ folders and .pyc files) are now always excluded from sdists
Use tomllib in Python 3.11, rather than tomli
Fix crash when unable to get a password from keyring
Fix including modified files in sdist when using Mercurial
Fix for some cases of determining whether a package supports Python 2 or not
Fix parsing version number from code using multiple assignments
Document how to use a PyPI token with FLIT_PASSWORD
Fix link to information about environment variables for pip
Link to the docs for the latest stable version in package metadata
Remove a mention of the toml package, which is no longer needed, from the Developing Flit page
The bootstrap install script for flit_core accepts a new --install-root option.
Ensure the license file is included in packages on PyPI

(adam)