[Minor] Add 2025-10 API version

[lizkenyon]

Description

Fixes #1408 and #1401

Shopify Admin REST API version 2025-10 is a cleanup release that removes deprecated endpoints while maintaining all other existing
functionality. The removed resources include:

• AccessScope - Apps can no longer query granted access scopes via REST API
• Product - Legacy product endpoints removed (migration to GraphQL Admin API required)
• ProductImage - Legacy product image endpoints removed
• PriceRule - Legacy discount system endpoints removed
• ProductListing - Product listing management for sales channels removed
• ProductResourceFeedback - Product resource feedback system removed

How has this been tested?

Please, describe the tests that you ran to verify your changes.

Checklist:

• My commit message follow the pattern described in here
• I have performed a self-review of my own code.
• I have added tests that prove my fix is effective or that my feature works.
• I have updated the project documentation.
• I have added a changelog line.

[JoaoFagundes]

thank you for your work here @lizkenyon! Do you mind clarifying on the endpoints removed? I couldn't find mentions to this in Shopify's Changelog. Will the endpoints keep working in case I have a fork version from the gem and keep the resource there?