Removes line items from the specified checkout.
The removeLineItems() function returns a Promise that resolves to the updated checkout when the line items are removed from the specified checkout.
ID of the checkout to remove line items from.
IDs of the line items to be removed.
To find the IDs of the checkout line items you'd like to remove, pass the checkout._id to getCheckout() and look for the IDs under lineItems and/or customLineItems.