x11-drivers/xf86-video-dummy: Update to 0.4.1

Update WWW, LICENSE and pkg-descr.
Switch from pkg-plist to PLIST_FILES.

https://lists.x.org/archives/xorg-announce/2022-April/003155.html
https://lists.x.org/archives/xorg-announce/2023-May/003394.html

PR: 296430
Approved by: x11 (arrowd)
Approved by: osa (mentor)