chore(release): 6.8.0 [skip ci]

# [6.8.0](https://gitlab.com/to-be-continuous/python/compare/6.7.0...6.8.0) (2024-04-02)

### Features

* add GCP auth variant ([0188ac9d](https://gitlab.com/to-be-continuous/python/commit/0188ac9d4aa8e952060ebc3e485a7c298cc5d4b0))