Test building from distroless image

[ways]

For example from https://github.com/GoogleContainerTools/distroless

[ways]

Existing container:
ghcr.io/metno/sedr 0.11.0 80b96c3ca30d 45 hours ago 318MB

With distroless I can get it down to:
sedr latest 22fccecfb843 4 seconds ago 200MB

[ways]

No noticeable change in runtime.

[ways]

@havardf Do you have an opinion on this? See PR.

Distroless is recommended in https://sikkerhet.nav.no/docs/sikker-utvikling/containere#distroless, but it's probably more relevant for running services.