Merge branch '238191-hide-the-upgrade-link-on-the-admin-license-page-if-the-current-plan-is-ultimate' into 'master'

Hide the upgrade link on the admin license page if plan Ultimate

Closes #238191

See merge request gitlab-org/gitlab!40977

Deprecate GlSkeletonLoading component

See merge request gitlab-org/gitlab!40994

Restore doorkeeper generator to hex due to breaking change

See merge request gitlab-org/gitlab!41169

Document the 'Access denied for your LDAP account' error

See merge request gitlab-org/gitlab!38835

Update empty state behavior for incidents list

See merge request gitlab-org/gitlab!40872

Boards Sidebar state

See merge request gitlab-org/gitlab!40553

Extract Theme specific CSS and load through startup.css

Closes #241465

See merge request gitlab-org/gitlab!40503

This moves all themes for the navbar themes to their own file
Inlines them for startup css or loads them
On theme selection we load all themes

Merge branch '238111-count-of-the-number-of-self-hosted-smtp-configurations-by-package' into 'master'

Add mail.smtp_server to usage ping data

See merge request gitlab-org/gitlab!39844

Make file upload button on MR edit page tab-accessible

See merge request gitlab-org/gitlab!40995

- no need to show how-to-upgrade link if
  we are already on the highest possible.

Quarantine failing multi-project_pipelines_spec.rb

See merge request gitlab-org/gitlab!41128

Doorkeeper 5.1 changed the default token generator to urlsafe_base64
from hex. This restores the generator to hex to avoid the breaking
change.

Add push mirroring use case for regulated companies

See merge request gitlab-org/gitlab!40735

Docs: dev FF follow-up

Closes #241470 and #241504

See merge request gitlab-org/gitlab!40518

- Improve order
- Add note saying dev FFs != GL's FFs
- Link to presentation

Add Microsoft and Google style guides as backups

See merge request gitlab-org/gitlab!39791

Update incident docs

See merge request gitlab-org/gitlab!41078

Add run and debug instructions for monitor specs

See merge request gitlab-org/gitlab!39100

Update Chrome & Chromedriver to version 85 in the QA image

See merge request gitlab-org/gitlab!41100

Add custom metric importer

See merge request gitlab-org/gitlab!37773

Use dompurify on individual issue fields

See merge request gitlab-org/gitlab!41044

Bump doorkeeper to 5.3.0

See merge request gitlab-org/gitlab!40929

Simplify the Review App deployment by leveraging response from API call

See merge request gitlab-org/gitlab!41095

Fix Lint/UriRegexp cop

See merge request gitlab-org/gitlab!41117

Update Gitaly version

See merge request gitlab-org/gitlab!41141

Remove GIT_SSL_NO_VERIFY from DS docs

See merge request gitlab-org/gitlab!39528

Added test for Vulnerabilities::FindingSerializer

See merge request gitlab-org/gitlab!40462

Fix Style/MultilineIfModifier cop

See merge request gitlab-org/gitlab!41113

Clarify that a license is needed for the Elastic settings

See merge request gitlab-org/gitlab!41138

NOT NULL constraint to target_project_id column

Closes #233507

See merge request gitlab-org/gitlab!40836