gpui: Unify track_scroll method to receive a reference type (#43518)

Release Notes:

- N/A

This PR to change the `track_scroll` method to receive a reference type
like the
[Div#track_scroll](https://docs.rs/gpui/latest/gpui/trait.StatefulInteractiveElement.html#method.track_scroll),
[Div#track_focus](https://docs.rs/gpui/latest/gpui/trait.InteractiveElement.html#method.track_focus).


```diff
- .track_scroll(self.scroll_handle.clone())
+ .track_scroll(&self.scroll_handle)

- .vertical_scrollbar_for(self.scroll_handle.clone(), window, cx)
+ .vertical_scrollbar_for(&self.scroll_handle, window, cx)
```


https://github.com/zed-industries/zed/blob/56a2f9cfcf0c6a3c38f596b58002953763cd890f/crates/gpui/src/elements/div.rs#L1088-L1093


https://github.com/zed-industries/zed/blob/56a2f9cfcf0c6a3c38f596b58002953763cd890f/crates/gpui/src/elements/div.rs#L613-L620

crates/language_tools/src/syntax_tree_view.rs

@@ -507,11 +507,11 @@ impl Render for SyntaxTreeView {
                             }),
                         )
                         .size_full()
-                        .track_scroll(self.list_scroll_handle.clone())
+                        .track_scroll(&self.list_scroll_handle)
                         .text_bg(cx.theme().colors().background)
                         .into_any_element(),
                     )
-                    .vertical_scrollbar_for(self.list_scroll_handle.clone(), window, cx)
+                    .vertical_scrollbar_for(&self.list_scroll_handle, window, cx)
                     .into_any_element()
                 } else {
                     let inner_content = v_flex()