Add 'closed_at' attribute to Issues API

Closes #5935

See merge request gitlab-org/gitlab-ce!14316

Eliminate N+1 queries in loading discussions.json endpoint

Closes #37955

See merge request gitlab-org/gitlab-ce!14327

Fix mini graph pipeline breaking in merge request view

Closes #37590

See merge request gitlab-org/gitlab-ce!14306

Add missing import statements

See merge request gitlab-org/gitlab-ce!14209

Fixes milestone issuable assignee URL

Closes #33124

See merge request gitlab-org/gitlab-ce!14292

Merge branch '37933-improve-new-project-page-description-explaining-what-a-project-is' into 'master'

Resolve "Improve “New project“ page description explaining what a project is"

Closes #37933

See merge request gitlab-org/gitlab-ce!14331

Clean up read_registry scope changes

Closes #37789

See merge request gitlab-org/gitlab-ce!14307

Fix docs for lightweight tag creation via API

Closes #17499

See merge request gitlab-org/gitlab-ce!14328

In #37955,we see that the profile had a number of N+1 queries from repeated
access to `cross_reference_not_visible_for?`. This was optimized in previous
versions of GitLab by rendering all notes at once, counting the number of
visible references, and then using that number to check whether a system note
should be fully redacted.

There was also another N+1 query calling `ProjectTeam#member?`, which did not
take advantage of an optimization in prepare_notes_for_rendering that would
preload the maximum access level per project.

Closes #37955

Fix notification message when admin label was modified

See merge request gitlab-org/gitlab-ce!14330

Closes #37789

Minor update to address Sean McGivern's comment.

See merge request gitlab-org/gitlab-ce!14311

Explain what a project is instead of what a user can do

Replace the 'project/snippets.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!14326

Use correct group members path for members flyout link

Closes #37957

See merge request gitlab-org/gitlab-ce!14329

Fix broken link in docs/api/wiki.md

See merge request gitlab-org/gitlab-ce!14296

Prepare Repository#merge for migration to Gitaly

Closes gitaly#559

See merge request gitlab-org/gitlab-ce!14154

Never connect to webpack-dev-server over SSL in dev mode

See merge request gitlab-org/gitlab-ce!14297

Extract AutocompleteController#users into finder

Closes #24121

See merge request gitlab-org/gitlab-ce!13778

Replace the 'project/commits/revert.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!14325

Replace the 'project/archived.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!14322

Update build images

See merge request gitlab-org/gitlab-ce!14315

Improve 'spec/features/profiles/*' specs

Closes #37855 et #37856

See merge request gitlab-org/gitlab-ce!14317

Replace the 'search.feature' spinach test with an rspec analog

See merge request gitlab-org/gitlab-ce!14248

Clean up redirect routes that conflict with regular routes

Closes #36229

See merge request gitlab-org/gitlab-ce!13783

IssueNotes: Fix role badge styling.

See merge request gitlab-org/gitlab-ce!14279

Remove gaps under nav on build page

Closes #37857

See merge request gitlab-org/gitlab-ce!14283

Change Pipelines to CI/CD for Settings page

See merge request gitlab-org/gitlab-ce!14168

# Conflicts:
#   doc/ci/variables/README.md

Add Security Concerns section to reply by email documentation

[ci skip]

See merge request gitlab/gitlabhq!2191