contextvars.Context
Similar changes to the ones @sobolevn made in #6942
Also remove the python2 markers of packages that don't list Python 2 as supported in the latest version. Don't special case version '0.1' Co-authored-by: Akuli <akuviljanen17@gmail.com>
See discussion in #2491 Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>