Test: at the minimum width on macOS the main menu may be the folded Menu button (#6920)

The menu bar folds titles that don't fit into "⋯", or all of them into one "Menu" when not even
the first fits. On hosted macOS, at MIN_WINDOW_SIZE, the bar is the Menu button (the system font is
wider), so the test's File menu item wasn't there and it failed; the main menu is still reachable.
A real macOS window uses the native menu bar.

crates/ui-egui/tests/it/min_window.rs

@@ -26,7 +26,12 @@ fn at_the_minimum_width_the_modes_fold_into_a_menu_and_search_stays() {
     h.get_by_role_and_label(Role::Button, "E-Sign").click();
     h.run_steps(4);
     assert!(h.query_by_role_and_label(Role::Button, "E-Sign").is_some(), "the menu button is named after the mode");
-    assert!(h.query_by_role_and_label(Role::MenuItem, "File").is_some(), "main menu reachable");
+    // The menu bar folds the titles that don't fit into "⋯", or all of them into one "Menu" when not
+    // even the first fits (craft-menu's `MenuBarUi`). macOS's system font is wider, and at this width
+    // the bar is the "Menu" button there; a real macOS window has the native menu bar instead.
+    let menus = |label| h.query_by_role_and_label(Role::MenuItem, label).is_some();
+    let folded = cfg!(target_os = "macos") && menus("Menu");
+    assert!(menus("File") || folded, "main menu reachable");
 }
 
 #[test]