gnu: Vorta: Remove a transitive dependency on QtWebKit.

See <https://issues.guix.gnu.org/53289> for more information about this change.

* gnu/packages/backup.scm (vorta)[inputs]: Replace python-pyqt with
python-pyqt-without-qtwebkit.

gnu/packages/backup.scm

@@ -1321,7 +1321,7 @@ borgmatic is powered by borg.")
            python-paramiko
            python-peewee
            python-psutil
-           python-pyqt
+           python-pyqt-without-qtwebkit
            python-secretstorage
            ;; This is included so that the qt-wrap phase picks it up.
            qtsvg))