Remove insecure and unmaintained qtwebkit

see https://lists.opensuse.org/archives/list/factory@lists.opensuse.org/thread/GXVEFT7VY5DQNATX6FHJBQBRDHRC3NRN/, https://bugs.gentoo.org/684580.

switch to webengine:

• community/alkimia: https://github.com/KDE/alkimia/blob/master/CMakeLists.txt#L92
• community/kmymoney: https://github.com/KDE/kmymoney/blob/master/CMakeLists.txt#L256
• testing/notepadqq: update to v2.0.0-beta for https://github.com/notepadqq/notepadqq/pull/669
• community/ktorrent: https://github.com/KDE/ktorrent/commit/f5a1958ebdcacac8dd22a43623356dbf6bf6c34a

remove webkit dep:

• community/rocs: https://github.com/KDE/rocs/commit/e1171bfaecb9c719b89f8ed04d60ad76ea4088dd
• community/shotcut: https://github.com/mltframework/shotcut/commit/a44fe75a4dc7410668935cd0d3470994f5997571
• community/umbrello: https://gitweb.gentoo.org/repo/gentoo.git/tree/kde-apps/umbrello/files/umbrello-20.08.3-no-qtwebkit.patch
• testing/recoll: https://framagit.org/medoc92/recoll/-/commit/504705879b7ad900b9f3924ca959978f8619c815

remove package:

• community/qt5-qtwebkit
• community/kdewebkit: kde wrapper for qtwebkit
• community/wkhtmltopdf: basically unmaintained upstream, and wanted special qtwebkit patches anyways. (less featured) alternatives exist, and those who want insecure implementation should download binary manually (and run in a sandbox...)
• testing/py3-pdfkit: requires wkhtmltopdf