Remove Terraform CI/CD templates
This is part of a larger set of issues which migrate GitLabs current Terraform CI/CD templates to OpenTofu CD/CD components.
This issue is about removing the Terraform CI/CD templates (for self-managed and SaaS).
Specifically this includes the following template files:
- https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform.gitlab-ci.yml
- https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform.latest.gitlab-ci.yml
- https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform/Base.gitlab-ci.yml
- https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/ci/templates/Terraform/Base.latest.gitlab-ci.yml
... and the associated documentation.
The deprecation announcement happens in %16.9 with Deprecate the Terraform CI/CD templates (#438010)