I tried UK configurator and one of the standard equipment listed was "Omission of charging cable for household socket". So not standard equipment anymore in UK it seems. I have but never used and doubt I will
I presume you have made a typing error. As it is commonly called a "Granny cable". UK cars are not supplied with one. If you are desperate for one, you can purchase one online. They come with various cable lengths for next-day delivery.