gnu: Make nothing depend on QtWebKit.

This is required for <https://issues.guix.gnu.org/53289>.

* gnu/packages/qt.scm (python-pyqt)[inputs]: Remove qtwebkit.
(python-pyqt-without-qtwebkit): Remove variable.
(python-pyqtwebengine)[inputs]: Replace python-pyqt-without-qtwebkit with
python-pyqt.
* gnu/packages/backup.scm (vorta)[inputs]: Likewise.
* gnu/packages/ebook.scm (calibre)[inputs]: Likewise.
[arguments]: Adjust accordingly.
* gnu/packages/education.scm (anki)[inputs]: Replace
python-pyqt-without-qtwebkit with python-pyqt.
* gnu/packages/kde-games.scm (kajongg)[inputs]: Likewise.
* gnu/packages/maths.scm (veusz)[inputs]: Likewise.
* gnu/packages/music.scm (frescobaldi)[inputs]: Likewise.
(picard)[inputs]: Likewise.
* gnu/packages/orange.scm (orange)[inputs]: Likewise.
* gnu/packages/pdf.scm (flyer-composer)[inputs]: Likewise.
* gnu/packages/python-check.scm (python-pytest-qt)[propagated-inputs]: Likewise.
* gnu/packages/python-xyz.scm (python-qtconsole)[propagated-inputs]: Likewise.
(python-pyqtgraph)[propagated-inputs]: Likewise.
* gnu/packages/radio.scm (gnuradio)[inputs]: Likewise.
* gnu/packages/video.scm (openshot)[inputs]: Likewise.
* gnu/packages/vpn.scm (openconnect-sso)[inputs]: Likewise.
* gnu/packages/web-browsers.scm (qutebrowser)[inputs]: Likewise.

gnu/packages/backup.scm

@@ -1343,7 +1343,7 @@ borgmatic is powered by borg.")
            python-paramiko
            python-peewee
            python-psutil
-           python-pyqt-without-qtwebkit
+           python-pyqt
            python-secretstorage
            ;; This is included so that the qt-wrap phase picks it up.
            qtsvg-5))