Merge branch '296504-broken-master-spec-controllers-dashboard-projects_controller_spec-rb-39' into 'master'

Fix: spec/controllers/dashboard/projects_controller_spec.rb:39

See merge request gitlab-org/gitlab!50742

Add `DAST_AUTH_VALIDATION_URL` docs

See merge request gitlab-org/gitlab!50716

Quarantine export file download spec in staging only and update issue link

See merge request gitlab-org/gitlab!50706

Unified auth for NuGet package manager

See merge request gitlab-org/gitlab!38627

Update WEBrick to v1.6.1

See merge request gitlab-org/gitlab!50720

- Add an auth builder system to improve API auth
- Use new system for NuGet
- NuGet now requires usernames to be valid when authenticating with a
  PAT or deploy token

Add `dismissal_reason` argument to the `VulnerabilityDismiss` mutation

See merge request gitlab-org/gitlab!50688

Ruby ships with WEBrick v1.6.0, but v1.6.1 contains a fix for a CVE:
https://bugs.ruby-lang.org/issues/17201

We only use WEBrick for Sidekiq exporter to serve internal metrics, so
this CVE shouldn't be a user-facing issue.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/296224

Experiment user  context column to get merged rather than overridden

See merge request gitlab-org/gitlab!50684

The current behavior is being overridden

Add link to issue in issue due email

See merge request gitlab-org/gitlab!50642

Update feature categories for 2020-12-31

See merge request gitlab-org/gitlab!50709

- plus a test.

https://gitlab.com/gitlab-com/www-gitlab-com/-/merge_requests/70219
reorganised some of these categories. Most of the items that were under
`collection` can go to `usage_ping`, but the historical usage export
probably belongs under `provision` (as it's to do with license usage),
and the survey response are - tangentially - under `navigation`.

Quarantines flaky Usage Data Specs

See merge request gitlab-org/gitlab!50708

See tracking issue https://gitlab.com/gitlab-org/gitlab/-/issues/296169

Enlarge the timeline toggle button

See merge request gitlab-org/gitlab!50284

Grafana annotations for database reindexing

See merge request gitlab-org/gitlab!50194

* Introduce observer-like pattern.
* Refactor ReindexAction.keep_track_of and split

Use a dynamic segment not depending on the package id for Debian files

See merge request gitlab-org/gitlab!50433

Add project pipeline statistics test case for variable length months

See merge request gitlab-org/gitlab!50704

- 31st day of the month
- February in non-leap year

Revert "Merge branch '226988-notify-email_participants-instead-of-external_author' into 'master'"

See merge request gitlab-org/gitlab!50699

This reverts merge request !48823

Added documentation for new terraform list actions

See merge request gitlab-org/gitlab!50660

Add allowed to push superseding codeowners for web ide

See merge request gitlab-org/gitlab!50608

This argument will provide better structured dismissal reason tracking.

[DevOps Adoption] Daily updates - part 2

See merge request gitlab-org/gitlab!50416

Improve code readability in nuget search service

See merge request gitlab-org/gitlab!50667

Merge branch 'scalability/665-create-introductory-documentation-and-tutorial-about-stage-group-dashboards' into 'master'

Create introductory documentation and tutorial about Stage Group dashboards

See merge request gitlab-org/gitlab!50570

To allow easy migration of package files from incoming to the target
package.

Fix lint issues

See merge request gitlab-org/gitlab!50677

Introduce dismissal reason for vulnerability feedback

See merge request gitlab-org/gitlab!50632