In Qt-5.12, the order of the dependency between these two packages
flipped.
A symptom of the problem is an error like, `module
"QtQuick.XmlListModel" is not installed`.
The upstream changes that this reflects are in qtxmlpatterns
<8c6e24329e>
and qtdeclarative <0477a057fd>
This is the first time since 5.9 that we also update `qtwebkit`.
`qtwebkit` is not maintained by Qt anymore and thus, we switch to the
community port as for example arch has done. To prevent pulling in
single patches, we just stick to the latest git version.