Note: This is just for `gitlab-org/gitlab`. ## Action items - [x] For the main `Gemfile.lock` and `Gemfile.next.lock` files, upgrade to [Bundler 2.6](https://bundler.io/blog/2024/12/19/bundler-v2-6.html) - [x] Run `bundle lock --add-checksums`. Also run `bundle lock --normalize-platforms` (https://bundler.io/blog/2024/12/19/bundler-v2-6.html#should-i-take-any-other-steps-before-enabling-this-feature) - [x] Stop using `BUNDLER_CHECKSUM_VERIFICATION_OPT_IN` on master - [x] Update the upgrade strategy of [renovate-gitlab-bot](https://gitlab.com/gitlab-org/frontend/renovate-gitlab-bot/-/tree/main/renovate/gitlab) (example: [1](https://gitlab.com/gitlab-org/frontend/renovate-gitlab-bot/-/blob/main/renovate/gitlab/ruby.config.js#L217),[2](https://gitlab.com/gitlab-org/frontend/renovate-gitlab-bot/-/blob/main/renovate/gitlab/bundle-install-next.sh),[3](https://gitlab.com/gitlab-org/frontend/renovate-gitlab-bot/-/blob/main/renovate/gitlab/bundle-checksum.sh#L22)) - [x] Verify no adverse impact on Omnibus, Charts and source installs - [x] Deprecate [`bundler-checksum`](vendor/gems/bundler-checksum) and possibly remove it. Probably the only usage is here, and also in https://gitlab.com/gitlab-org/frontend/renovate-gitlab-bot /cc @leipert @splattael @igor.drozdov @stanhu @clemensbeck @rmarshall