Automatically publish tagged releases to the GitLab terraform registry
Note that the pipeline for this MR will fail until uis/devops/continuous-delivery/ci-templates!28 (closed) is merged.
An example of a semver tagged module published via this CI configuration is at https://gitlab.developers.cam.ac.uk/uis/devops/infra/terraform/gcp-function/-/infrastructure_registry/418
This was published by https://gitlab.developers.cam.ac.uk/uis/devops/infra/terraform/gcp-function/-/pipelines/106036.
Closes #1 (closed)