This was done in 4099097381, likely
because netsurf includes utf8proc headers as <libutf8proc/utf8proc.h>
rather than <utf8proc.h>, as other applications do. Unfortunately, this
also made it so any application using utf8proc also had to be passed
custom CFLAGS, because the pkg-config file specified the include dir to
be /usr/include rather than /usr/include/libutf8proc.
Since a move to JuliaLang's utf8proc is likely, modernizing the package
ahead of that change also makes sense.
07e9866649