chore(release): 5.6.0 [skip ci]

# [5.6.0](https://gitlab.com/to-be-continuous/docker/compare/5.5.6...5.6.0) (2023-12-4)

### Features

* build cache can be disabled (configurable; non-default) ([fe52e0eb](https://gitlab.com/to-be-continuous/docker/commit/fe52e0ebd9f851c7976f240942e9917d396bc813))