Update generated code for v1540

OPENAPI_VERSION

@@ -1 +1 @@
-v1538
+v1540

lib/InvoiceItem.php

@@ -31,8 +31,6 @@
  * @property null|(string|\Stripe\Margin)[] $margins The margins which apply to the invoice item. When set, the <code>default_margins</code> on the invoice do not apply to this invoice item.
  * @property null|\Stripe\StripeObject $metadata Set of <a href="https://stripe.com/docs/api/metadata">key-value pairs</a> that you can attach to an object. This can be useful for storing additional information about the object in a structured format.
  * @property (object{end: int, start: int}&\Stripe\StripeObject&\stdClass) $period
- * @property null|\Stripe\Plan $plan If the invoice item is a proration, the plan of the subscription that the proration was computed for.
- * @property null|\Stripe\Price $price The price of the invoice item.
  * @property bool $proration Whether the invoice item was created automatically as a proration adjustment when the customer switched plans.
  * @property int $quantity Quantity of units for the invoice item. If the invoice item is a proration, the quantity of the subscription that the proration was computed for.
  * @property null|string|\Stripe\Subscription $subscription The subscription that this invoice item has been created for, if any.