This thing has been broken since a48dfc1d65 (v0.5.0 + 1) when the game
was upgraded to Bevy 0.17. Install the libwayland-dev package to get the
CI runner building correctly again.
I also increased the artifact retention period to 7 days... I'm not sure
I actually want to keep any artifacts, but if I'm going to then I should
keep them long enough for me to go back and look at them.