Backport EE MR

See merge request gitlab-org/gitlab-ce!29853

When using suggestions, squash must be enabled

See merge request gitlab-org/gitlab-ce!29687

Update e2e quick start document

See merge request gitlab-org/gitlab-ee!14280

https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14280

Run static memory benchmarks from 'derailed_benchmarks' in CI

See merge request gitlab-org/gitlab-ce!29618

Resolve "Username availability checker breaks inline validation"

Closes #62980

See merge request gitlab-org/gitlab-ce!29678

To keep it updated with the codebase.

See:

https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14276
and
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/28643

Knative version bump 0.5 -> 0.6

See merge request gitlab-org/gitlab-ce!28798

Adds missing class in collapsible sections

Closes #63417

See merge request gitlab-org/gitlab-ce!29804

Backport of 12014-incremental-es-wiki-updates

See merge request gitlab-org/gitlab-ce!29531

Enable incremental elasticsearch index updates for wikis

See merge request gitlab-org/gitlab-ee!14057

Docs: Correct upgrade guides for 12.0

See merge request gitlab-org/gitlab-ce!29846

Resolve "Multiple spec failures in './ee/spec/lib/gitlab/git_access_spec.rb'"

Closes #12278

See merge request gitlab-org/gitlab-ee!14272

It's fine to upgrade from 11.11.x to 12.x, so we remove the requirement
to first upgrade to 12.0.x.

Geo - Remove legacy queries from ProjectRegistryFinder, ExpireUploadsFinder, and RepositoryVerificationFinder

See merge request gitlab-org/gitlab-ee!14195

Will apply identation from
CSS to collapsible sections

Merge branch '63399-intermittent-spec-failure-in-spec-models-ci-pipeline_schedule_spec-rb-131' into 'master'

Resolve "Intermittent spec failure in spec/models/ci/pipeline_schedule_spec.rb:131"

Closes #63399

See merge request gitlab-org/gitlab-ce!29838

Refactor file locking docs

See merge request gitlab-org/gitlab-ce!29686

- Remove outdated 'introduced in' section
- Update/remove images

Fixes flaky master

Two static memory benchmarks will be included in our CI pipeline. It
will load gems from the Gemfile and check the amount of RAM consumed
as well as the number of objects allocated and retained.
Aggregated values will be included as 'metrics' into MRs while full
reports will be downloadable as job artifacts.

Feature spec for merge train

Closes #12081

See merge request gitlab-org/gitlab-ee!14090

Unquarantine the branches E2E test

Closes gitlab-org/quality/nightly#62

See merge request gitlab-org/gitlab-ce!29828

Docs: Added source upgrade guides for 12.0.0

See merge request gitlab-org/gitlab-ce!29795

Document Usage Quotas group settings page

Closes #63022

See merge request gitlab-org/gitlab-ce!29599