Add pipeline validation failure description

Closes #55695

See merge request gitlab-org/gitlab!21780

Resolve "All pages that render icons return 500"

See merge request gitlab-org/gitlab!21783

node_modules is cleaned up in Omnibus so this was causing errors
on all pages that rendered an icon

Update query limiting whitelist link

See merge request gitlab-org/gitlab!21741

Refactor the Deployment model so state machine events are used by both CI and the API

Closes #36648

See merge request gitlab-org/gitlab!20474

Backend data model for serverless domains

See merge request gitlab-org/gitlab!19835

Merge branch '36402-update-start-trial-cta-in-top-right-banner-to-only-appear-if-all-namespaces-are-free' into 'master'

Update start trial CTA in top right banner to only appear if all namespaces are free

See merge request gitlab-org/gitlab!20177

Implement external validation during pipeline creation

Closes #34015

See merge request gitlab-org/gitlab!21134

Stubs out the major elements of the external validation pipeline chain
step.

Changes database engineer to just engineer

See merge request gitlab-org/gitlab!21774

Rectifies Database Query Comments guide to just use Engineer instead of
DB engineer, as we don't have those on call

Block empty params to MR target branch autocompletion

Closes #31830

See merge request gitlab-org/gitlab!21748

Show correct warning on issue when project is archived

See merge request gitlab-org/gitlab!20078

Fix assignee url issue in board sidebar

Closes #35842

See merge request gitlab-org/gitlab!20992

Add doc for blame and history UI functionality

Closes #39106

See merge request gitlab-org/gitlab!21609

While the functionality was created ~ 7 years ago, it was never doc'd

Resolve "Link Group name on group's Admin page"

See merge request gitlab-org/gitlab!21709

Merge branch '38056-change-the-clipboardtext-property-requirement-inside-the-panel_type-component' into 'master'

Change the `clipboardText` to optional in panel_type component

Closes #38056

See merge request gitlab-org/gitlab!21717

Remove var from app/assets/javascripts/commit/image_file.js

Closes #36266

See merge request gitlab-org/gitlab!21649

Upgrade @sentry/browser to 5.10.2

See merge request gitlab-org/gitlab!21702

Update static ip link

See merge request gitlab-org/gitlab!21770

Add child label to commit box (2/3)

See merge request gitlab-org/gitlab!21323

Refactor end-to-end test to make it more robust

Closes #36688

See merge request gitlab-org/gitlab!21652

And simpler.

Resolve "Replace fa-bullhorn with GitLab SVG bullhorn icon (all instances)"

Closes #41934

See merge request gitlab-org/gitlab!21587

Marginalia with feature check on app start

See merge request gitlab-org/gitlab!21364

Switch to DockerHub for Elasticsearch image

See merge request gitlab-org/gitlab!21750

Changelog entries for MRs 21524 and 21607

See merge request gitlab-org/gitlab!21768

Skip updating LFS objects in mirror updates if repository has not changed

Closes #38256

See merge request gitlab-org/gitlab!21744

We were being rate-limited by docker.elastic.co:

```
Unavailable: Back-end server is at capacity (executor_docker.go:188:0s)
elasticsearch : 5.6.12
```

[ci skip]