chore(release): 3.0.0 [skip ci]

# [3.0.0](https://gitlab.com/to-be-continuous/helmfile/compare/2.1.0...3.0.0) (2023-09-26)

* feat!: support environment auto-stop ([c0e94d78](https://gitlab.com/to-be-continuous/helmfile/commit/c0e94d78182ffb0166c391bed7131f7689e48cf8))

### Features

* add $kube_namespace ctx variable ([7d93ae70](https://gitlab.com/to-be-continuous/helmfile/commit/7d93ae70f7131010c78f33ded577225dbe259235))

### BREAKING CHANGES

* now review environments will auto stop after 4 hours
by default. Configurable (see doc).