[Shipping Labels] Editing customs form doesn't get saved

[selanthiraiyan]

Issue

Editing the customs form doesn't get saved while retrying to load label rates.

Steps to reproduce

1. Create an order that requires filling custom form while purchasing shipping labels.
2. Open the order detail page -> Tap "Create Shipping Label"
3. Fill out the custom form so the loading labels request fails with an error.
4. Select a package
5. Intercept the /wcshipping/v1/label/rate&_method=post request and check the customs form related parameters.
6. Edit the details in the customs form.
7. Edit the package weight to load the labels rate again.
8. Intercept the /wcshipping/v1/label/rate&_method=post request, and you can see that the latest saved customs form information is not sent in the request.

Expected behaviour

1. The /wcshipping/v1/label/rate&_method=post request should use the latest filled info from the customs form.
2. The labels rate request should be resent as soon as the customs form is saved.

Screen recording

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-03-26.at.14.15.40.mp4

[dangermattic]

🚫 Please add a type label (e.g. type: enhancement) and a feature label (e.g. feature: stats) to this issue.