x11-toolkits/qtermwidget: Update to 0.8.0

While here, set maintainer to maintainer of other lxqt related ports, Jesper
Schmitz Mouridsen <jesper@schmitz.computer>

PR: 223221
Submitted by: Olivier Duchateau <duchateau.olivier@gmail.com>
Approved by: Jason Bacon <bacon4000@gmail.com> (maintainer)