Removes a specified product from the cart.
について removeProduct() function returns a Promise that resolves to the
updated cart after the product is removed.
Every line item in a cart has an ID. Pass this to removeProduct() to remove that line item/product from the cart.
注釈
removeProduct() does not decrement the line item's quantity, it removes the line item/product altogether.removeProduct() will only work when viewing the live site.
ID of the cart line item to remove.