Update stylo for latest changes. (#33079)

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/layout_2020/display_list/mod.rs

@@ -840,7 +840,7 @@ impl<'a> BuilderForBoxFragment<'a> {
                     // TODO: Add support for PaintWorklet rendering.
                 },
                 Image::ImageSet(..) | Image::CrossFade(..) => {
-                    unreachable!("Shouldn't be parsed on Servo for now")
+                    // TODO: Add support for ImageSet and CrossFade rendering.
                 },
             }
         }