Enable clippy::clone_on_copy (#8728)

This PR enables the
[`clippy::clone_on_copy`](https://rust-lang.github.io/rust-clippy/master/index.html#/clone_on_copy)
rule and fixes the outstanding violations.

Release Notes:

- N/A

crates/editor/src/display_map.rs

@@ -1291,7 +1291,7 @@ pub mod tests {
 
         let mut cx = EditorTestContext::new(cx).await;
         let editor = cx.editor.clone();
-        let window = cx.window.clone();
+        let window = cx.window;
 
         _ = cx.update_window(window, |_, cx| {
             let text_layout_details =