Style schemes are not translated

data/style-schemes/builder-dark.xml and data/style-schemes/builder.xml are not extracted to .pot/.po files:

xgettext: warning: file 'data/style-schemes/builder-dark.xml' extension 'xml' is unknown; will try C xgettext: warning: file 'data/style-schemes/builder.xml' extension 'xml' is unknown; will try C

These files still have the intltool underscores, which gettext doesn’t support.