Make use of the centralised renovate configuration introduced by
uis/devops/renovate-config!204 so that downstream modules have one fewer
thing to keep in sync.

Addresses uis/devops/infra/gitlab-bots-deployment#79 at the same time
since the centralised configuration includes automerge support.

Closes uis/devops/renovate-config#33

Closes uis/devops/infra/gitlab-bots-deployment#79

feat: use centralised terraform module renovate configuration

Closes uis/devops/renovate-config#33 and uis/devops/infra/gitlab-bots-deployment#79

See merge request !60