.github: drop xtrans dependency

[metux]

We don't need external xtrans anymore - we've now have our own (heavily modified) copy.

This btw is one of the repos that often makes transient build errors.

[metux]

converting to draft: this doesn't work so easily, because xproto et al for funny reaons demand xtrans - even though they don't actually need it.

[EXtremeExploit]

guthub...