Update python-sip, sip4 request

Hello, In the ROS community, a lot of developers use the 'python-orocos-kdl' library, https://github.com/orocos/orocos_kinematics_dynamics, which generates its python bindings with SIP. The versions of SIP between 4.16.7 and 4.19.20 contain bugs which make the 'python-orocos-kdl' hard to use.

Re: Bug#938819: wheel: Python2 removal in sid/bullseye

Hi Dmitry, čt 30. 1. 2020 v 22:38 odesílatel Dmitry Shachnev napsal: > However upstream python-keyring has dropped Python 2 support, and I want > to upgrade to a newer release, so Python 2 support will be dropped sooner > or later. > upstream drop of Python 2 support doesn't mean you need to dr