Add a gitlab-tofu user for debian/alpine images
- Use sh in both images, seperate jobs per user
This creates seperate jobs for the users, with root being built first, followed by gitlab-opentofu user image. This is done to prevent matrix explosions which cause massive numbers of jobs to occur
- Add a gitlab-tofu user for debian/alpine images
Enables images with either root or gitlab-opentofu as the user
replaces: !432 (closed)
relates to: #172 (closed)