[Non-Touch] Don't add touch-related menu items (#8608)

They were ending up orphaned as "New:" in the top menu first tab.

frontend/apps/reader/modules/readerhighlight.lua

@@ -356,6 +356,12 @@ function ReaderHighlight:addToMainMenu(menu_items)
         }
     end
     menu_items.translation_settings = Translator:genSettingsMenu()
+
+    if not Device:isTouchDevice() then
+        -- Menu items below aren't needed.
+        return
+    end
+
     menu_items.long_press = {
         text = _("Long-press on text"),
         sub_item_table = {