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

[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

Stablize register spec

See merge request gitlab-org/gitlab!50675

Migrate to native window scrolling

See merge request gitlab-org/gitlab!43167

We can replace jquery.scrollTo.js with commonUtils scrollToElement or
native browser scrolling.

Quarantine flaky default branch name setting spec

See merge request gitlab-org/gitlab!50645

Fix project export audit log spec

See merge request gitlab-org/gitlab!50644

Add Packages::Debian::GetOrCreateIncomingService

See merge request gitlab-org/gitlab!50431

Minor API readme style updates

See merge request gitlab-org/gitlab!50670

[RUN ALL RSPEC] Deprecations job

See merge request gitlab-org/gitlab!49792