Display cancellation notice for S&R product

[OlfatProgressus]

All Submissions:

• Does your code follow WooCommerce and WordPress standards?
• Have you successfully run tests with your changes locally?
• Have you tested both blocks/non-blocks cart/checkout?
• Have you tested the cart and checkout as both a logged-in user and a guest?
• Have you successfully placed an order as both a logged-in user and a guest?
• Did you have the query monitor plugin active during all testing?

Changes proposed in this Pull Request:

Closes # .
Task url

How to test the changes in this Pull Request:

1. Open PostNL settings page and check the Shipping & Return Label option
2. You should find a note added to the option and the description ( Note: Shipment & Return Label will be discontinued on July 1. )

Other information:

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changelog entry

Enter a summary of all changes on this Pull Request. This will appear in the changelog if accepted.