fix: The alphabet also closes when the launchpad is shut down

as title.

PMS-BUG-289179

Author: wjyrich

qml/windowed/AppListView.qml

@@ -386,5 +386,13 @@ FocusScope {
                 }
             }
         }
+        Connections {
+            target: LauncherController
+            function onVisibleChanged() {
+                if (!LauncherController.visible) {
+                    alphabetCategoryPopup.close()
+                }
+            }
+        }
     }
 }