Fix References header parser for Microsoft Exchange

Closes #26567

See merge request !8620

Don't use backup AR connections for Sidekiq

Closes #27713

See merge request !9001

Issue filters in boards modal

Closes #26205

See merge request !8903

Remove coverage entry from global CI/CD options

See merge request !8981

Adding GitLab Pages to CE

Closes #14605, gitlab-com/infrastructure#1058, gitlab-ee#1333, and #323

See merge request !8463

Rename example from file_name to file_path

Closes #27643

See merge request !8959

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8620#note_22868713

Add traits for ProjectFeatures to Project factory

Closes #24007

See merge request !8925

Update NFS HA doc with location -> config mapping

Closes #27685

See merge request !8993

Added specs for merge request environment list

See merge request !8937

Don't render snippet actions for logged-out users

Closes #27708

See merge request !8995

Resolve "Remove hover animation from row elements"

Closes #26863

See merge request !8842

V4 API: Remove deprecated MR and Issue endpoints and preserve V3 namespace

Closes #27180

See merge request !8967

Adding two extra connections does nothing other than increasing the
number of idle database connections. Given Sidekiq uses N threads it can
never use more than N AR connections at a time, thus we don't need more.

The initializer mentioned the Sidekiq upgrade guide stating this was
required.  This is false, the Sidekiq upgrade guide states this is
necessary for Redis and not ActiveRecord.

On GitLab.com this resulted in a reduction of about 80-100 PostgreSQL
connections.

Fixes #27713

# Conflicts:
#   db/schema.rb

Make all system notes lowercase

See merge request !8807

Modify the search bar area on admin/projects page

Closes #26794

See merge request !8776

Resolves user avatar flickers as you type

Closes #27602

See merge request !8950

Use babel to transpile all non-vendor javascript assets regardless of file extension

See merge request !8988

fix ace editor modules to include asset digest in production

See merge request !8869

Introduce maximum session time for terminal websocket connection

Closes #26263

See merge request !8413

Unify projects search by removing /projects/:search endpoint

Closes #22007

See merge request !8877

API: Fix file downloading

See merge request !8953

Store the value in application settings.
Expose the value to Workhorse.