Default to -listenfd on Plasma 6 even if xwayland.pc isn't present
Someone using Plasma 6 won't be running XWayland from 4+ years ago, but they might not have xwayland.pc
correctly available on their system.
I just ran into this on Arch Linux on Plasma 6, would be nice if support could just be assumed true from 6 onwards.
Or just throw an error if xwayland.pc
isn't available and force maintainers to add a --no-xwayland flag to build anyway, so maintainers cannot miss the fact that their kwin is built without proper XWayland support.
Downstream issue: https://gitlab.archlinux.org/archlinux/packaging/packages/kwin/-/issues/3
Relevant issue/MR: #127 (closed) !739 (merged)
Edited by Martin Rys