Make Shipping Address Optional on new checkout UI

🔍 Problem Statement
The Shipping Address section on the new checkout UI displays by default and cannot be hidden, even for plans that don't require shipping information.

💡 User Story
As a business owner, I want the Shipping Address field to show or hide dynamically based on the shipping requirement configured on the selected plan, so that customers aren't shown irrelevant fields at checkout.

🎯 Definition of Done (DoD)
✔ Given a plan configured without a shipping address requirement, when a subscriber reaches checkout, then the Shipping Address section is not displayed.

✔ Given a plan configured with a shipping address requirement, when a subscriber reaches checkout, then the Shipping Address section is displayed and required.

✔ This change will impact UI, specifically the checkout Shipping Address section.