Fix macOS traffic light position when performing a project search (#55310)

Regression introduced in #48029, applying the same workaround here that
we seem to use for `setDocumentEdited`

Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- (Preview only) Fixed an issue on macOS where the traffic light
position would be wrong when opening the project search

crates/gpui_macos/src/window.rs

@@ -1482,6 +1482,10 @@ impl PlatformWindow for MacWindow {
             let filename = path.map_or(ns_string(""), |p| ns_string(&p.to_string_lossy()));
             let _: () = msg_send![window, setRepresentedFilename: filename];
         }
+
+        // Changing the document path state resets the traffic light position,
+        // so we have to move it again.
+        self.0.lock().move_traffic_light();
     }
 
     fn show_character_palette(&self) {