Remove kdewebkit from the CI job seeds.

Due to the unmaintained status (and removal) of QtWebKit with openSUSE we have dropped it from our images, meaning kdewebkit can no longer be built.

All projects are advised that they should also be dropping any dependency they have on kdewebkit / QtWebKit as it is no longer supported within a CI system context.

CCMAIL: kde-frameworks-devel@kde.org
CCMAIL: kde-core-devel@kde.org
CCMAIL: kde-devel@kde.org
CCMAIL: kde-pim@kde.org
CCMAIL: kmymoney-devel@kde.org