Bump version to 2.23.0
Bump version to 2.23.0

For API additions, and unstable work.

YueLinHo/MB3Gdk-pixbuf,djdeath/gdk-pixbuf,GNOME/gdk-pixbuf,Distrotech/gdk-pixbuf,djdeath/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,Distrotech/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,GNOME/gdk-pixbuf,Distrotech/gdk-pixbuf,djdeath/gdk-pixbuf,Distrotech/gdk-pixbuf,GNOME/gdk-pixbuf,djdeath/gdk-pixbuf,YueLinHo/MB3Gdk-pixbuf,GNOME/gdk-pixbuf,Distrotech/gdk-pixbuf