ci: Bump Ruby/RubyGems versions in CI images
This follows gitlab-build-images!835 (merged) but since the Git version was already updated, I took the opportunity to update the Ruby/RubyGems versions instead.
Edited by Rémy Coutable
This follows gitlab-build-images!835 (merged) but since the Git version was already updated, I took the opportunity to update the Ruby/RubyGems versions instead.