Fixed resolved discussions not toggling expanded on changes tab

Closes #51370

See merge request gitlab-org/gitlab-ce!21676

Fix column differences in `db/schema.rb`

See merge request gitlab-org/gitlab-ce!21718

Add project to jupyter cluster app factory spec

See merge request gitlab-org/gitlab-ce!21717

Document abstraction levels and code reuse

See merge request gitlab-org/gitlab-ce!21254

This is based on the discussion in
https://gitlab.com/gitlab-org/gitlab-ce/issues/49653 and the example
merge request found at
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20908. The idea
is fairly straightforward: we define a variety of abstractions, then
state which can reuse which. This should ultimately foster _better_ code
reuse, make it easier to debug problems, and make it harder to
accidentally introduce a performance regression.

Add RuboCop cops to enforce code reusing rules

See merge request gitlab-org/gitlab-ce!21391

Enable omniauth by default

Closes #49990

See merge request gitlab-org/gitlab-ce!21700

Display click to expand on collapsed diffs

Closes #51466

See merge request gitlab-org/gitlab-ce!21716

project_custom_attributes and group_custom_attributes used datetime
instead of datetime_with_timezone column type in database schema. But
actually migration defines `t.timestamps_with_timezone`.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Merge branch '50808-choosing-initialize-repo-with-a-readme-breaks-project-created-from-template' into 'master'

Resolve "Choosing “Initialize repo with a README” breaks project created from template"

Closes #50808

See merge request gitlab-org/gitlab-ce!21646

Vendor Auto-DevOps.gitlab-ci.yml: fix where the deploy job does not wait for Deployment to complete.

Closes #50186 and charts/auto-deploy-app#6

See merge request gitlab-org/gitlab-ce!21713

Vendor Auto-DevOps.gitlab-ci.yml for refactor to create registry_login() function.

Closes #51450

See merge request gitlab-org/gitlab-ce!21714

Fix route deprecation warnings in rails 5

See merge request gitlab-org/gitlab-ce!21684

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51370

Merge branch '42861-move-include-external-files-in-gitlab-ci-yml-from-starter-to-libre' into 'master'

Resolve "Move "include external files in .gitlab-ci.yml" from Starter to Libre"

Closes #42861

See merge request gitlab-org/gitlab-ce!21603

Vendors in Auto-DevOps.gitlab-ci.yml from
https://gitlab.com/gitlab-org/gitlab-ci-yml/merge_requests/195

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/50186

Vendor Auto-DevOps.gitlab-ci.yml from https://gitlab.com/gitlab-org/gitlab-ci-yml/merge_requests/193

Thanks @LaurentGoderre, for your contribution !

Strip whitespace from Sentry URL

Closes #49621

See merge request gitlab-org/gitlab-ce!21703

[ci skip]

Resolve "500 Internal Server Error: Deleting branch of deleted project"

Closes #50678

See merge request gitlab-org/gitlab-ce!21542

Adding extra whitespace in the DSN could prevent the server from
starting due to InvalidURIErrors in sentry-raven.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/49621

Remove Rugged and shell code from Gitlab::Git

Closes gitaly#1124

See merge request gitlab-org/gitlab-ce!21488

Fix mention in edit mr

Closes #50608

See merge request gitlab-org/gitlab-ce!21696

Log project services sidekiq failures

Closes #50528

See merge request gitlab-org/gitlab-ce!21336

Use GitLab UI pagination component for groups

See merge request gitlab-org/gitlab-ce!21287

Update gitlab shell

See merge request gitlab-org/gitlab-ce!21701

Update code_review.md to include a recommendation for assigning maintainers from different teams

See merge request gitlab-org/gitlab-ce!21644

Initialize projects with readme

See merge request gitlab-org/gitlab-ce!21617