chore(ci variables): update the ci_variables.json

This change is generated automatically by running npm run update-ci-variables. There is no need to validate the content (variable names, descriptions) because it's parsed from the GitLab documentation. The only thing to review is to sanity check the JSON.

Docs describing this process: https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/blob/main/docs/ci-variables.md