knot: Enable XDP and DoQ

Alpine Linux 3.17 supports XDP, which has the potential to be much more performant than normal network traffic. However, Knot DNS is currently not compiled with support for it enabled.

This can be seen by looking at the recent build log. That will also show that it does not have support for DNS-over-QUIC included: I am also looking to use that, and would like it enabled as well.