Add CI for ETOS

[t-persson]

Description

We need some CI for ETOS that is fully automatic and always works.

Motivation

This will reduce the manual workload for ETOS maintainers.

Exemplification

Wanting to set up a gitops workflow that tracks the latest commit on each component is basically impossible today since we have to build everything manually.

Benefits

This will allow us to better test each release of ETOS.

Possible Drawbacks

We will build a lot of containers and push to nordix