Update accesskit_winit and dark_light (#2655)

* Update accesskit_winit to 0.8.1

* Update dark_light to 1.0

crates/eframe/src/epi.rs

@@ -429,6 +429,7 @@ impl NativeOptions {
             match dark_light::detect() {
                 dark_light::Mode::Dark => Some(Theme::Dark),
                 dark_light::Mode::Light => Some(Theme::Light),
+                dark_light::Mode::Default => None,
             }
         } else {
             None