Fix misgenerated QHoverEvent
https://doc.qt.io/qt-6/qhoverevent.html#oldPos
https://doc.qt.io/qt-6/qhoverevent-obsolete.html#pos
oldPos: On QEvent::HoverEnter events, this position will always be QPoint(-1, -1).
pos: On QEvent::HoverLeave events, this position will always be QPoint(-1, -1).
On the same app, such as Wayland-enabled VS Code, the misgeneration causes the cursor to move to the origin when moving the cursor away from the server side decoration.
(cherry picked from commit aa57e913)