Fix streaming serializer for serialize_many_each

Closes #212607

See merge request gitlab-org/gitlab!28138

Quarantine additional QA test

See merge request gitlab-org/gitlab!28127

Make Rails.cache and Gitlab::Redis::Cache use the same pool

See merge request gitlab-org/gitlab!28074

Hide helm application row if local tiller

See merge request gitlab-org/gitlab!24742

- Bad merge, method name changed to write_relation_array

Fix Spring Loading Wrong Instrumentation Class

See merge request gitlab-org/gitlab!28051

Add support for project_members array

Closes #212457

See merge request gitlab-org/gitlab!28025

Use GlAlert component for design list load error

See merge request gitlab-org/gitlab!28079

Quarantine several manage QA tests

See merge request gitlab-org/gitlab!28117

Make sure the shards table has its index created before populating it

Closes #212436

See merge request gitlab-org/gitlab!28084

Refactor JSON reader/writer for import/export

See merge request gitlab-org/gitlab!27679

- adds `allowed_path` to strong validate `LegacyReader`
  and `LegacyWriter`
- does not change any of todays behaviour for data serialization
- makes the interface for reader and writer to accept
  `importable/exportable_path` that will be used by `ndjson`
  to store data in separate files
- moves consuming of attributes outside of the relation tree restorer
  to ease the way how we process them
- splits specs for `LegacyReader::User/File` and introduces
  shared example for that: this is also the majority of changes
  introduced by this MR in order to move them
- slightly code-formats and re-organises group and project
  import/export

Return error message in custom metric validation when prometheus URL is blocked

See merge request gitlab-org/gitlab!27863

Fix optional params for deploy token API

Closes #211878

See merge request gitlab-org/gitlab!27961

Unified views for Project and Personal snippets

See merge request gitlab-org/gitlab!27998

Document how to delete images from the Container Registry

Closes #32669

See merge request gitlab-org/gitlab!27622

Document the various ways of deleting images from the Container
Registry.

Replace set to let_it_be in spec

See merge request gitlab-org/gitlab!28004

Merge branch '208433-follow-up-from-add-mutation-concern-to-resolve-a-single-issuable-part-2' into 'master'

Use ResolvesIssuable for Epics

Closes #208433

See merge request gitlab-org/gitlab!27903

Use 'license_scanning' in controller tests

See merge request gitlab-org/gitlab!27819

Fixes the file row icons hiding when the shouldn't be

See merge request gitlab-org/gitlab!28110

Log member additions when importing Project/Group

See merge request gitlab-org/gitlab!27930

Use prefix search instead of ngrams for sha fields

See merge request gitlab-org/gitlab!27597

Currently, SHAs are indexed using ngrams from 5 to 40 characters. This
means that each SHA is split into 35 separate terms taking up a lot of
storage. SHAs are quite unique from 4-5 characters on, so a simple
prefix search will be sufficiently fast and as effective as ngrams with
term matching. This change replaces current sha fields analyzers with
prefix search.

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

Improve Group Security Dashboard performance

See merge request gitlab-org/gitlab!27959

Add feature flag to highest role callback

See merge request gitlab-org/gitlab!28105

Docs: Create MR from a fork

Closes #199227

See merge request gitlab-org/gitlab!28111

Docs add packages url to updates

See merge request gitlab-org/gitlab!27762

Remove forward npm package request feature flag

See merge request gitlab-org/gitlab!27987

Updated text to stress importance of the requirements

See merge request gitlab-org/gitlab!27027

Add language around Cloudflare IPs

See merge request gitlab-org/gitlab!28010

See https://about.gitlab.com/blog/2020/01/16/gitlab-changes-to-cloudflare/ for details.

Update GitLab Runner Helm Chart to 0.15.0/12.9.0

See merge request gitlab-org/gitlab!27670

Put the update highest role callback for Members behind a feature flag
because there needs to be an additional callback when a User does not
count as active anymore.