pip: add support for Python 3.12. (#9614)

pip: fix typo. (#9481)

This silly typo prevented the inclusion of `/bin/{pip,pip3}`
along with `/bin/pip-3.10` (for the default Python version,
it is always nice to provide non-version-suffixed commands).

pip: update to version 23.2.1 (#9308)

Also: drop 3.8, add 3.11 support.