Enhance EmbeddedCheckoutPopup to prevent default behavior on escape key down (#278)

- Added an onEscapeKeyDown handler to the EmbeddedCheckoutPopup component to prevent default actions when the escape key is pressed, improving user experience and accessibility.

packages/billing/stripe/src/components/stripe-embedded-checkout.tsx

@@ -65,6 +65,7 @@ function EmbeddedCheckoutPopup({
         className={className}
         onOpenAutoFocus={(e) => e.preventDefault()}
         onInteractOutside={(e) => e.preventDefault()}
+        onEscapeKeyDown={(e) => e.preventDefault()}
       >
         <DialogTitle className={'hidden'}>Checkout</DialogTitle>
         <div>{children}</div>