Fix CI test failing in `stable/2.8.x` #14967

Job	Run time
Set up docker build 'dynamic' env variables	1s
Build and check documentation	3m 23s
Run the Django test suite	7m 33s
End-to-end tests, chromium	13m 9s
Run the Django test suite in reverse	5m 31s
End-to-end tests, firefox	16m 15s
End-to-end tests, webkit	11m 55s
docker_build (production) / Build image	2m 50s
docker_build (extensions, token_exchange,prefill_haalcentraalhr, all-extensions-) / Build image	2m 52s
Scan docker image	2m 4s
Simulate upgrading instances (2.7.4)	1m 22s
Simulate upgrading instances (2.7.8)	1m 24s
Check for unexepected OAS changes	3s
Generate SDKs from OAS	32s
Validate OAS	20s
Generate Postman collection from OAS	9s
Push Docker image	0s
update-docker-readme	0s
	1h 9m 23s

Provide feedback