Fix dock resizing

crates/collab_ui/src/collab_panel.rs

@@ -2391,8 +2391,8 @@ impl Panel for CollabPanel {
             .unwrap_or_else(|| settings::get::<CollaborationPanelSettings>(cx).default_width)
     }
 
-    fn set_size(&mut self, size: f32, cx: &mut ViewContext<Self>) {
-        self.width = Some(size);
+    fn set_size(&mut self, size: Option<f32>, cx: &mut ViewContext<Self>) {
+        self.width = size;
         self.serialize(cx);
         cx.notify();
     }