ci: security scanning not running in MR pipelines

Checklist

  • I'm using the latest version of the extension (Run glab --version)
    • Extension version: Put your extension version here
  • Operating System and version: _Put your version here

Summary

By default, jobs from Secure templates don't run on MRs. gitlab#217668 (closed)

main MR
image image

Possible fixes

Similar to the GitLab VS Code Extension, we need to enable the security scanning for MRs https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/blob/43270d78de6370dc62aeeeb380c3757ff0082028/.gitlab-ci.yml#L149-174