awscliv2 since v2.8.0 has not been buildable on Funtoo, since they have switched to a pep517 compatible build process.

The thing is that they use flit as their builder, but the pyproject.toml file defines:

`build-backend = "pep517"`

This causes portage to throw the following error:

` * Build system packages:
 *   dev-python/gpep517            : 9
 *   dev-python/installer          : 0.5.1-r1
 *   dev-python/flit_core          : 3.7.1
>>> Source prepared.
>>> Configuring source in /var/tmp/portage/app-admin/awscliv2-2.8.2/work/awscliv2-2.8.2 ...
>>> Source configured.
>>> Compiling source in /var/tmp/portage/app-admin/awscliv2-2.8.2/work/awscliv2-2.8.2 ...
 * python3_7: running distutils-r1_run_phase distutils-r1_python_compile
 * ERROR: app-admin/awscliv2-2.8.2::core-server-kit failed (compile phase):
 *   Unknown backend: pep517`