Upgrade gitlab-shell to 9.2.0

See merge request gitlab-org/gitlab-ce!28372

Add haml-lint.yml to FE for roulette

See merge request gitlab-org/gitlab-ce!28301

Main change is to bump .ruby-version to 2.6.3 so versions
are consistent for the GDK.

Resolve CE/EE diffs in admin user access levels

Closes gitlab-ee#10507

See merge request gitlab-org/gitlab-ce!28359

Resolve CE/EE diffs in mirror repos settings

Closes gitlab-ee#11036

See merge request gitlab-org/gitlab-ce!28361

Explain render_if_exists opts caveat

See merge request gitlab-org/gitlab-ce!28366

Document what to do if review jobs keep failing

See merge request gitlab-org/gitlab-ce!28367

CE backport of "Configure the number of ES shards and replicas"

See merge request gitlab-org/gitlab-ce!28329

Signed-off-by: Rémy Coutable <remy@rymai.me>

Omit max-count for diverging_commit_counts behind feature flag

See merge request gitlab-org/gitlab-ce!28157

Changed the placeholder text of the diff tree filter input

Closes #58339

See merge request gitlab-org/gitlab-ce!28352

Disallow the review-deploy and review-qa-smoke jobs to fail

See merge request gitlab-org/gitlab-ce!28314

Add :registrations_recaptcha feature flag

Closes gitlab-ee#11389

See merge request gitlab-org/gitlab-ce!28296

Fix. db:migrate is failed on MySQL 8

See merge request gitlab-org/gitlab-ce!28351

Resolve "Error 500 viewing admin/projects page: undefined method `storage_size' for nil:NilClass"

Closes #49915

See merge request gitlab-org/gitlab-ce!28355

Explain `render_if_exists` relative path

See merge request gitlab-org/gitlab-ce!28356

Resolve CE/EE diffs in _flash_messages

Closes gitlab-ee#11037

See merge request gitlab-org/gitlab-ce!28333

Part of single codebase changes.

Signed-off-by: Rémy Coutable <remy@rymai.me>

Part of single codebase changes.

Update Rubocop to 0.69.0 and other gems

See merge request gitlab-org/gitlab-ce!28345

Fixes style-lint issues for blocks.scss

Closes #59838

See merge request gitlab-org/gitlab-ce!28251

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/58339

Allows instance owners to toggle the recaptcha requirement
on the user registration page by feature flag.
Allows GitLab Growth team to measure
reCAPTCHA's impact on registrations.

Include MR information if possible when emailing notification of closing an issue

Closes #19569

See merge request gitlab-org/gitlab-ce!15610

CE backport of "Fix a broken spec for EE"

See merge request gitlab-org/gitlab-ce!28357

Signed-off-by: Rémy Coutable <remy@rymai.me>

Part of single codebase changes.

Fixes issues with show whitespace button in diffs

Closes #42597 and #58852

See merge request gitlab-org/gitlab-ce!28242

```
StandardError: An error has occurred, all later migrations canceled:

Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'system = true AND note LIKE '\_%\_'' at line 1: UPDATE notes SET note = trim(both '_' from note) WHERE system = true AND note LIKE '\_%\_'
```

Add Let's Encrypt client

See merge request gitlab-org/gitlab-ce!27624

Part of adding Let's Encrypt certificates for pages domains

Add acme-client gem

Client is being initialized by private key stored in secrets.yml
Let's Encrypt account is being created lazily.
If it's already created, Acme::Client just gets account_kid by
calling new_account method

Make Let's Encrypt client an instance
Wrap order and challenge classes

Properly clear the merge error upon rebase failure

Closes #56139

See merge request gitlab-org/gitlab-ce!28319

i18n JS files starting with i

See merge request gitlab-org/gitlab-ce!28010

Resolve CE/EE diffs in help/index

Closes gitlab-ee#11051

See merge request gitlab-org/gitlab-ce!28335