Add article on autoscaling GitLab Runner on AWS

Closes #39650

See merge request gitlab-org/gitlab-ce!15313

Update prometheus Gem to fix compilation on centos 6 due to GCC not recognizing `std=c11` option

Closes omnibus-gitlab#2988

See merge request gitlab-org/gitlab-ce!15598

Fix ProtectedBranch access level validations

See merge request gitlab-org/gitlab-ce!15586

Drastically improve project search performance by no longer searching namespace name

Closes #40510 and #39623

See merge request gitlab-org/gitlab-ce!15590

Add a feedback mechanism to `package-qa` manual action

Closes #40431

See merge request gitlab-org/gitlab-ce!15538

Previously these were duplicated so they could be different for push/merge,
but this was no longer necessary after
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/11232

Before an access_level was required in EE even when an
it had been set for a user/group.

Resolve "Update timeago.js"

Closes #40465

See merge request gitlab-org/gitlab-ce!15553

Fix WIP system note not being created

Closes #40374

See merge request gitlab-org/gitlab-ce!15528

Prevent 500 error when inspecting job after trigger was removed

Closes #36400

See merge request gitlab-org/gitlab-ce!15447

Add classList polyfill for IE classList.toggle('foo', force)

Closes #38916

See merge request gitlab-org/gitlab-ce!15552

Fix pulling and pushing using a personal access token with the sudo scope

Closes #40466

See merge request gitlab-org/gitlab-ce!15571

Update Prometheus Gem version and disable Prometheus method call instrumentation by default.

Closes gitlab-ee#4139 and #40457

See merge request gitlab-org/gitlab-ce!15558

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38916

[ci skip]

Fix hashed storage for attachments bugs

Closes #40280

See merge request gitlab-org/gitlab-ce!15482

Clean up repository fetch and mirror methods

See merge request gitlab-org/gitlab-ce!15424

Fixed import of render mermaid & render math methods

See merge request gitlab-org/gitlab-ce!15550

Renamed ProtectedBranches::ApiUpdateService to LegacyApiUpdateService

See merge request gitlab-org/gitlab-ce!15575

Simplify the DB changes checklist

See merge request gitlab-org/gitlab-ce!15577

Move identical merged branch check to merged_branch_names

Closes #39887

See merge request gitlab-org/gitlab-ce!15464