USPS provider uses deprecated API

[jtnicholl-cosairus]

The USPS provider is calling the USPS Web Tools API, which is long deprecated and will be shut down completely on January 25, 2026.

https://www.usps.com/business/web-tools-apis/welcome.htm

The current APIs are documented here: https://developers.usps.com/apis

[ahwm]

We've started getting a message from the API about this instead of an XML rate request. That makes the USPS provider completely unusable for right now.

[ahwm]

I just revamped our integration for a client. They only needed rates calculation and very basic values, but hopefully this will help:

https://gist.github.com/ahwm/c49c4e5949d01f2b5533e28ee46d0654