chore(release): 4.0.0 [skip ci]

# [4.0.0](https://gitlab.com/to-be-continuous/cnb/compare/3.1.0...4.0.0) (2025-02-04)

### Bug Fixes

* replace default builder image (obsolete) ([05a23804](https://gitlab.com/to-be-continuous/cnb/commit/05a238046d7f976615204bcc76d9443c17488639))

### BREAKING CHANGES

* The change of the default builder image might cause regressions in existing projects.

More info about why the former Ubuntu Bionic-based images were unsafe: https://blog.paketo.io/posts/paketo-bionic-builder-is-unsafe/