QEMU VM should use phone like video mode

(Although this is likely not the perfect place for this but since this spans several projects I'll put it here):

We want the QEMU VM have a phone like resolution by default. Therefore we need to

• Support this in wlroots: https://github.com/swaywm/wlroots/pull/1095
• Update our wlroots/rootston (either with a new upstream version or the patches from above)
• Add the right configuration to rootston.ini, luckily QXL uses a specific output name (Virtual-1):

[output:Virtual-1]
modeline = 87.25  720 776 848 976  1440 1443 1453 1493 -hsync +vsync
mode = 720x1440
scale = 2