Remove local env variable for version and update template version

This MR does the following:

• Removes the local environment variable in order to consider the one coming from Dockerfile
• Update the same version within the template file and its related spec
• Add default command as part of the Dockerfile to simplify stand-alone scanning
• Add .tool-versions into .gitignore for those who are using asdf as recommended by GDK/GitLab main repository

It was required after !9 (merged)