Fix scroll area not consuming scroll events (#7904)

This fixes scrolling in a nested scroll area also scrolling the outer
scroll area


https://github.com/user-attachments/assets/ade40b1e-c974-4806-8045-881bea590d4a

Author: lucasmerlin

crates/egui/src/containers/scroll_area.rs

@@ -1198,10 +1198,9 @@ impl Prepared {
                         // Clear scroll delta so no parent scroll will use it:
                         ui.input_mut(|input| {
                             if always_scroll_enabled_direction {
-                                input.smooth_scroll_delta()[0] = 0.0;
-                                input.smooth_scroll_delta()[1] = 0.0;
+                                input.smooth_scroll_delta = Vec2::ZERO;
                             } else {
-                                input.smooth_scroll_delta()[d] = 0.0;
+                                input.smooth_scroll_delta[d] = 0.0;
                             }
                         });