Fix input validation regression for edit grids #11797

Job	Run time
Set up docker build 'dynamic' env variables	1s
Build and check documentation	2m 12s
End-to-end tests, chromium	11m 8s
Run the Django test suite	6h 0m 18s
End-to-end tests, firefox	13m 25s
End-to-end tests, webkit	11m 42s
Run the Django test suite in reverse	5m 46s
docker_build (extensions, token_exchange,prefill_haalcentraalhr, all-extensions-) / Build image	6m 50s
docker_build (production) / Build image	6m 57s
Scan docker image	2m 7s
Check for unexepected OAS changes	0s
Validate OAS	0s
Generate Postman collection from OAS	0s
Generate SDKs from OAS	0s
Push Docker image	0s
update-docker-readme	0s
	7h 0m 26s

Provide feedback