This reverts commit a2031de849.
The patch itself seems OK, but it exposes a bug in lxml or libxml2-2.9.12 which
was just released. This is being resolved in
https://gitlab.gnome.org/GNOME/libxml2/-/issues/255, but it might be while. So
let's revert this for now to unbreak our CI.
Fixes#19601.