Adding terraform fmt to the Terraform template

Fix https://gitlab.com/gitlab-org/gitlab/-/issues/339935

Changelog: added

lib/gitlab/ci/templates/Terraform.latest.gitlab-ci.yml

@@ -16,6 +16,9 @@ stages:
 init:
   extends: .terraform:init
 
+fmt:
+  extends: .terraform:fmt
+
 validate:
   extends: .terraform:validate
 

lib/gitlab/ci/templates/Terraform/Base.latest.gitlab-ci.yml

@@ -28,6 +28,14 @@ cache:
     - cd ${TF_ROOT}
     - gitlab-terraform init
 
+.terraform:fmt: &terraform_fmt
+  stage: validate
+  needs: []
+  script:
+    - cd ${TF_ROOT}
+    - gitlab-terraform fmt -check -recursive
+  allow_failure: true
+
 .terraform:validate: &terraform_validate
   stage: validate
   script: