rename platform_versions.tf to versions.tf

[dms1981]

A reference to the issue / Description of it

#8272

How does this PR fix the problem?

Renames our template files from platform_versions.tf to versions.tf. This will mean that the copied files are no longer subject to the **/platform_*.tf @ministryofjustice/modernisation-platform glob pattern in our CODEOWNERS file.

How has this been tested?

Confirmed that scripts used to provision member directories will still copy the renamed files.

Deployment Plan / Instructions

No deployment required. A following PR will rename platform_versions.tf to versions.tf in the Modernisation Platform repository.

Checklist (check x in [ ] of list items)

• I have performed a self-review of my own code
• All checks have passed
• I have made corresponding changes to the documentation
• Plan and discussed how it should be deployed to PROD (If needed)

Additional comments (if any)

{Please write here}

[github-actions]

Trivy Scan Success

Show Output

```hcl

---

Trivy will check the following folders:
terraform/templates/modernisation-platform-environments-isolated
terraform/templates/modernisation-platform-environments

---

Running Trivy in terraform/templates/modernisation-platform-environments-isolated
Skipping folder as path name contains templates

---

Running Trivy in terraform/templates/modernisation-platform-environments
Skipping folder as path name contains templates

</details> #### `Checkov Scan` Success
<details><summary>Show Output</summary>

```hcl

*****************************

Checkov will check the following folders:
terraform/templates/modernisation-platform-environments-isolated
terraform/templates/modernisation-platform-environments

*****************************

Running Checkov in terraform/templates/modernisation-platform-environments-isolated
Skipping folder as path name contains *templates*

*****************************

Running Checkov in terraform/templates/modernisation-platform-environments
Skipping folder as path name contains *templates*

CTFLint Scan Success

Show Output

*****************************

Setting default tflint config...
Running tflint --init...
Installing "terraform" plugin...
Installed "terraform" (source: github.com/terraform-linters/tflint-ruleset-terraform, version: 0.9.1)
tflint will check the following folders:
terraform/templates/modernisation-platform-environments-isolated
terraform/templates/modernisation-platform-environments

*****************************

Running tflint in terraform/templates/modernisation-platform-environments-isolated
Skipping folder as path name contains *templates*
tflint_exitcode=0

*****************************

Running tflint in terraform/templates/modernisation-platform-environments
Skipping folder as path name contains *templates*
tflint_exitcode=0

Trivy Scan Success

Show Output

*****************************

Trivy will check the following folders:
terraform/templates/modernisation-platform-environments-isolated
terraform/templates/modernisation-platform-environments

*****************************

Running Trivy in terraform/templates/modernisation-platform-environments-isolated
Skipping folder as path name contains *templates*

*****************************

Running Trivy in terraform/templates/modernisation-platform-environments
Skipping folder as path name contains *templates*

[richgreen-moj]

LGTM