Don't add a quick actions toolbar item for non-editor views

Rather than adding primary toolbar item that renders as empty,
don't add an item at all. This prevents spurious spacing from
being added after other primary toolbar items.

crates/quick_action_bar/src/quick_action_bar.rs

@@ -152,9 +152,10 @@ impl ToolbarItemView for QuickActionBar {
                                 cx.notify();
                             }
                         }));
-                }
-
                     ToolbarItemLocation::PrimaryRight { flex: None }
+                } else {
+                    ToolbarItemLocation::Hidden
+                }
             }
             None => {
                 self.active_item = None;