[#4886] Allow `text/plain` for csv uploads #14877

Job	Run time
End-to-end tests, chromium	13m 32s
End-to-end tests, chromium	13m 32s
Set up docker build 'dynamic' env variables	1s
Set up docker build 'dynamic' env variables	1s
Build and check documentation	3m 26s
Build and check documentation	3m 26s
End-to-end tests, firefox	17m 19s
End-to-end tests, firefox	16m 13s
End-to-end tests, webkit	12m 44s
End-to-end tests, webkit	12m 44s
Run the Django test suite	8m 23s
Run the Django test suite	8m 23s
Run the Django test suite in reverse	5m 44s
Run the Django test suite in reverse	5m 44s
docker_build (production) / Build image	2m 52s
docker_build (production) / Build image	2m 52s
docker_build (extensions, token_exchange,prefill_haalcentraalhr, all-extensions-) / Build image	2m 41s
docker_build (extensions, token_exchange,prefill_haalcentraalhr, all-extensions-) / Build image	2m 41s
Scan docker image	2m 4s
Scan docker image	2m 4s
Simulate upgrading instances (2.7.4)	1m 31s
Simulate upgrading instances (2.7.4)	1m 31s
Simulate upgrading instances (2.7.8)	1m 29s
Simulate upgrading instances (2.7.8)	1m 29s
Check for unexepected OAS changes	15s
Check for unexepected OAS changes	15s
Generate Postman collection from OAS	18s
Generate Postman collection from OAS	18s
Generate SDKs from OAS	32s
Generate SDKs from OAS	32s
Validate OAS	16s
Validate OAS	16s
Push Docker image	0s
Push Docker image	0s
update-docker-readme	0s
update-docker-readme	0s
	2h 25m 8s

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