Fix support for loading SQL dumps in docker-compose #7971

Job	Run time
Build and check documentation	1m 36s
End-to-end tests, chromium	4m 14s
Check that documentation for configuration steps is up-to-date	1m 18s
End-to-end tests, firefox	5m 0s
End-to-end tests, webkit	4m 44s
Run the Django test suite (main)	20m 48s
End-to-end tests, msedge	4m 30s
Run the Django test suite (elastic)	5m 7s
Run the Django test suite (openklant)	2m 46s
Upload coverage information to codecov	14s
Build (and push) Docker image	1m 42s
	51m 59s

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