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

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

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

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

Resolve CE/EE diffs in signup_box

Closes gitlab-ee#11047

See merge request gitlab-org/gitlab-ce!28336

This fixes Ruby 2.6.x parser warnings:
https://github.com/rubocop-hq/rubocop/pull/7009

If `merge_error` is ever set after a failure, it is never cleared, even
after a subsequent, successful rebase. We now clear this field whenever
a successful rebase occurs.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56139

clarify that "team" means "project" when considered for assignment purposes.

See merge request gitlab-org/gitlab-ce!27753

Add info about the single docs codebase effort

See merge request gitlab-org/gitlab-ce!28127

Fix loadJSONFixtures wrapper in Jest

See merge request gitlab-org/gitlab-ce!28328

Mock away document.createRange() in Jest

See merge request gitlab-org/gitlab-ce!28222

i18n JS files starting with n

See merge request gitlab-org/gitlab-ce!28132

Merge branch 'ce-quick-fix-58727-collapsed-sidebar-flyout-menu-items-don-t-appear-in-1200px-screen-size' into 'master'

CE Fix flyout nav on small viewports

See merge request gitlab-org/gitlab-ce!25998

Sessions can be listed for a given user

See merge request gitlab-org/gitlab-ce!28306

Suppress keychain access popup from chromedriver in Karma

See merge request gitlab-org/gitlab-ce!28310

Docs: couple of improvements to the Vuex frontend guide

See merge request gitlab-org/gitlab-ce!28257

Update mysql.md: variables values should be quoted, otherwise you get an...

See merge request gitlab-org/gitlab-ce!24214

Update mysql.md: variables values should be quoted, otherwise you get an "variables config should be a hash of key value pairs" error

[CI doc] Add chat value to only keyword

See merge request gitlab-org/gitlab-ce!27417

recursive/nested includes supported now

See merge request gitlab-org/gitlab-ce!28155