size: Hardcode size to work around screen rotation
Phoc sends output information after changing keyboard surface size. Squeekboard adjusts size on surface events, but not on output in this revision, making it unaware of display size at the time of adjustment, resulting in bad adjustment.
This change hardcodes the proportions again to make it work at least on the Librem5.
I've also sneaked in Buster back into to CI because I can't wait for the battery to charge.