All Submissions:

• Have you followed the WooCommerce Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Created a new function to handle duplicate notices. While this was to address the shipping debug notices, it will also work in general to remove any duplicate notices.

Closes #28914

How to test the changes in this Pull Request:

1. Setup shipping with a valid zone/method.
2. Enable shipping debug mode by going to woocommerce->settings->shipping->shipping options
3. Add several items to the cart and navigate there
4. You should see the shipping debug message/notice of what zone location was detected.
5. Try deleting an item from the cart with the X button. After the AJAX process and the item is removed, ensure you are not seeing duplicate shipping debug message/notice.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully run tests with your changes locally?

Changelog entry

Fix - Cart duplicate debug shipping notices in certain situations.