If a user upgraded to any GitLab 11.x EE version but switched
back to CE, it's possible the state of the EE tables are not
in the right state for the EE backport migration to work properly.
In particular, there were three tables that had trouble:

* epics
* geo_event_log
* vulnerability_feedback

The EE backport migration would fail while trying to add foreign key
constraints because a key didn't exist in the table. This happens
because any EE migration that add or removed columns between v11.0.0 and
v11.11.3 are not guaranteed to be applied in an CE installation. The EE
backport schema does not individually backport these migrations.

We now check if certain columns are present to determine whether
the backport migration is in the proper state. CE users are required
to upgrade to v11.11.3 EE if they ever installed EE previously before
they can go back to v12.x CE.

Tested via:

```
git checkout -f v11.0.0-ee
bundle exec rake db:reset
git checkout .; git checkout -f v11.11.3
bundle exec rake db:migrate
git checkout .; git checkout -f v12.0.0
bundle exec rake db:migrate
<failure happens>
```

Renew pages domain's certificates through Let's Encrypt

See merge request gitlab-org/gitlab-ce!29363

Add index for pages domain ssl auto renewal
Add PagesDomain.needs_ssl_renewal scope
Add cron worker for ssl renewal
Add worker for ssl renewal
Add pages ssl renewal worker queues settings

Move `derailed_benchmarks` gem to :default group

See merge request gitlab-org/gitlab-ce!29975

Vue-i18n: autofix for app/assets/javascripts/jobs directory

See merge request gitlab-org/gitlab-ce!29969

Eliminate N+1 queries in Dashboard::TodosController

Closes #43042

See merge request gitlab-org/gitlab-ce!29954

Resolve "Runner tags search dropdown is empty"

Closes #63656

See merge request gitlab-org/gitlab-ce!29985

Since this scope is used in both the controller and the API, we rename
it to make it clear that it's used for both.

Revert "Fix copying a single line from Firefox"

See merge request gitlab-org/gitlab-ce!29993

This reverts merge request !29832

Add doc for ServiceResponse

Closes #62356

See merge request gitlab-org/gitlab-ce!29992

This appears to bring down the number of SQL queries on GitLab.com for
my Todos page from 672 to 100.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/43042

Require database reviews for migrations

See merge request gitlab-org/gitlab-ce!29895

Upgrade jquery to 3.4.1

See merge request gitlab-org/gitlab-ce!29980

Add column chart component to the monitoring bundle

See merge request gitlab-org/gitlab-ce!29293

Resolve "Avatar in "Please sign in" pattern too large"

Closes #63559

See merge request gitlab-org/gitlab-ce!29944

Render branch divergence graph with Vue

See merge request gitlab-org/gitlab-ce!29743

(CE Port) New user onboarding (Guided Tour)

See merge request gitlab-org/gitlab-ce!29927

- Add button styles for onboarding welcome page
- Fix qa selector (due to additional class)

Remove requirement for personal access token in profiling

See merge request gitlab-org/gitlab-ce!29972

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Build correct basenames for title search results

See merge request gitlab-org/gitlab-ce!29898

Add name & search parameters to project environments API

See merge request gitlab-org/gitlab-ce!29385

Resolve "Improved group lists UI"

Closes #52366

See merge request gitlab-org/gitlab-ce!26542

RSpec::Parameterized syntax for CI pipeline build seed specs

See merge request gitlab-org/gitlab-ce!29947

This updates the groups list UI to match the style of the project list:

- New layout
- Improve loading state when loading group children
- Larger, responsive text
- Icon and text colors changed to secondary
- Smaller button sizes
- Content list description colors were standardized to body text

Fix label serialisation in issue and note hooks

Closes #63473

See merge request gitlab-org/gitlab-ce!29850

Show create merge request button on confidential issues

See merge request gitlab-org/gitlab-ce!29688

Update tar to 2.2.2

See merge request gitlab-org/gitlab-ce!29949

Based on review comment fetching labels hook_attrs is now
wrapped in an issue's model method.

https://gitlab.com/gitlab-org/gitlab-ce/issues/58583

FIX: Scheduled pipelines scheduled to run at the same time as pipeline_schedule_worker gets pushed to the next run

Closes #63469

See merge request gitlab-org/gitlab-ce!29848

Automatically update MR merge-ref along merge status

See merge request gitlab-org/gitlab-ce!29569

Remove tooltip directive on project avatar image component

Closes #51990

See merge request gitlab-org/gitlab-ce!29631