Provide an option to lock on a specific version of scripts used from Gitlab templates

[mxr576]

Is there an existing issue for this?

• [x] I have searched the existing issues

Is your feature request related to a problem?

This is somewhat a follow-up on #154 but also a more general improvement. Currently, we always pull the latest changes from the gitlab_templates repository, which keeps us on the cutting edge but can introduce instability or unexpected behavior when upstream changes occur.

Describe your solution

We should reconsider this approach and, by default, lock to a specific tag from the available list here: https://git.drupalcode.org/project/gitlab_templates/-/tags This tag can then be updated periodically as needed.

Regardless of the default choice, we should also introduce an environment variable that allows consumer projects to lock onto a specific version of gitlab_templates and fetch scripts from there.

Describe alternatives

No response

Additional context

The list of files we borrow from gitlab_templates:

https://github.com/ddev/ddev-drupal-contrib/issues/154#issuecomment-3498493296

[weitzman]

Sounds good ... For clarity, we default to the most recent published release, not "latest changes" or "cutting edge".