Fix failure to start api/controller pods with tini as an entrypoint

[consideRatio]

ENTRYPOINT in a Dockerfile maps to command in a k8s Pod specification, and CMD in a Dockerfile maps to args in a k8s Pod specification. By defining args instead of command, we override the image's CMD but not its ENTRYPOINT and like that we end up successfully using tini as an entrypoint.

This change relates to this Dockerfile, that has a ENTRYPOINT aka command set to use tini.

dask-gateway/dask-gateway-server/Dockerfile

Lines 44 to 45 in fd2ada0

	ENTRYPOINT ["tini", "-g", "--"]
	CMD ["dask-gateway-server", "--config", "/etc/dask-gateway/dask_gateway_config.py"]