Upgrade Node.js to 20 (LTS)

Problem

Update Node.js to 20 because Node.js 18 active support ended and security support ends in 1 year. See https://endoflife.date/nodejs

  1. Update CustomersDot CI image in https://gitlab.com/gitlab-org/gitlab-build-images/ - gitlab-build-images!798 (merged)
  2. Add Node.js 20 to the Ansible repo - https://gitlab.com/gitlab-org/customersdot-ansible/-/merge_requests/523
  3. Bump .tool-versions and CI image - https://gitlab.com/gitlab-org/customers-gitlab-com/-/merge_requests/9804/

See &13545 (closed)

Edited by Vitaly Slobodin