Stripe primary payment method out of sync with Commerce's primary payment source

[timkelty]

Description

Commerce's concept of a customer's primary payment source does not properly sync with Stripe's primary payment method.

This is because every time we create a payment source in Stripe, we add it as the primary.

Conversely, Commerce will only default to an added source as primary if it is the only one.

Additionally, it is possible have an attached payment method in Stripe that is not primary.

Steps to reproduce

Using Commerce's example templates:

1. With a new customer, add a 1st payment source
   • Note that Commerce defaults this to being your "Primary"
2. Add a 2nd stripe payment source
   • Note that Commerce still considers the 1st to be primary
3. Look in Stripe, and the customer's 2nd card will be primary, while Commerce says 1st is primary.

Additional info

• Craft CMS version: 4.4.1
• Stripe for Craft Commerce version: 3.1.0
• PHP version: 8.1