alacritty update (wayland 0.31, vte 0.13, polling 3.x transitions)

Alacritty 0.13 requires updating the wayland stack to 0.31, vte to 0.13, and polling to 3.x. The wayland and polling changes are likely going to require updates in various other crates. The wayland crates are already staged in experimental as well as vte (but that needs a dependency to clear NEW before it will build). I'll post more details soon.