chore: Replace as_any functions with trait upcasting (#28221)

Closes #ISSUE

Release Notes:

- N/A

crates/ui/src/components/scrollbar.rs

@@ -33,10 +33,6 @@ impl ScrollableHandle for UniformListScrollHandle {
     fn viewport(&self) -> Bounds<Pixels> {
         self.0.borrow().base_handle.bounds()
     }
-
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
 }
 
 impl ScrollableHandle for ListState {
@@ -66,10 +62,6 @@ impl ScrollableHandle for ListState {
     fn viewport(&self) -> Bounds<Pixels> {
         self.viewport_bounds()
     }
-
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
 }
 
 impl ScrollableHandle for ScrollHandle {
@@ -107,10 +99,6 @@ impl ScrollableHandle for ScrollHandle {
     fn viewport(&self) -> Bounds<Pixels> {
         self.bounds()
     }
-
-    fn as_any(&self) -> &dyn Any {
-        self
-    }
 }
 
 #[derive(Debug)]
@@ -119,12 +107,11 @@ pub struct ContentSize {
     pub scroll_adjustment: Option<Point<Pixels>>,
 }
 
-pub trait ScrollableHandle: Debug + 'static {
+pub trait ScrollableHandle: Any + Debug {
     fn content_size(&self) -> Option<ContentSize>;
     fn set_offset(&self, point: Point<Pixels>);
     fn offset(&self) -> Point<Pixels>;
     fn viewport(&self) -> Bounds<Pixels>;
-    fn as_any(&self) -> &dyn Any;
     fn drag_started(&self) {}
     fn drag_ended(&self) {}
 }