testing/code-oss: missing many icon sizes
without them, it seems that gnome doesn't show the icon. flathub does this: https://github.com/flathub/com.visualstudio.code-oss/blob/a9dfe45f4ecf477af67285c57f5b672d4e60b26f/install-data.py#L98
without them, it seems that gnome doesn't show the icon. flathub does this: https://github.com/flathub/com.visualstudio.code-oss/blob/a9dfe45f4ecf477af67285c57f5b672d4e60b26f/install-data.py#L98