net/py-pyroute2.core: Add py-pyroute2.core 0.6.4

PyRoute2 is a pure Python netlink library.

This is the core package, it implements the netlink parser and several netlink
sockets, including RTNL (IPRoute), WireGuard, MPTCP etc.

WWW: https://github.com/svinota/pyroute2/tree/master/pyroute2.core