Fix FontWeight.Book value
Fix FontWeight.Book value

The pango font weight book is 380 according to
https://developer.gnome.org/pango/stable/pango-Fonts.html#PangoWeight

hwthomas/xwt,antmicro/xwt,cra0zy/xwt,lytico/xwt,TheBrainTech/xwt,hamekoz/xwt,residuum/xwt,mono/xwt,akrisiun/xwt