Rootless DinD sidecar

[viceice]

We now can use the renovate slim image with DinD sidecar.

The downside is, that the DinD container needs privileged security context

helm-charts/charts/renovate/templates/cronjob.yaml

Lines 132 to 133 in 0f1da58

	securityContext:
	privileged: true

So It would be nice to use to rootless DinD version, so we don't need a priviliged container.

[kvanzuijlen]

so we don't need a priviliged container

Not sure if this is the case, since according to the docs, privileged is still a requirement. I still think this is an improvement though since docker itself will run as a nonroot user (user id 1000).

[viceice]

closing in favor of:

• Drop DinD support in favor of install mode #298