- adds the field repository_update_events as json field

allowing override for EE.

This is a font from [Google](https://www.google.com/get/noto/).

Arch Linux [has a recommendation of it](https://wiki.archlinux.org/index.php/fonts#Emoji_and_symbols).

Add info about this into `docs/user/markdown.md#emoji`

This adds an endpoint to get the common ancestor of 2 refs from the API.

Closes #50143

fix design artifact label to be product discovery. Was done here https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20862 but not merged before this was moved.

Previously the key `git_ssh_url` was listed twice in the example payload of an Build Event web hook.

Signed-off-by: NRémy Coutable <remy@rymai.me>

Add details for https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20164.

Closes #49789.

This fixes gitlab-org/gitlab-ce#49953, as noted in the documentation
this feature is intended to be used when SSH certificates are
enabled. Then this warning becomes not only pointless, but also
misleading.

This builds on top of gitlab-org/gitlab-ce!21009 since both need to
modify the same documentation, which avoids a merge conflict.

See also the gitlab-org/gitlab-ce#49218 issue and associated merge
request.

The original link was moved.

This changes the BackgroundMigration worker so it checks for the health
of the DB before performing a background migration. This in turn allows
us to reduce the minimum interval, without having to worry about blowing
things up if we schedule too many migrations.

In this setup, the BackgroundMigration worker will reschedule jobs as
long as the database is considered to be in an unhealthy state. Once the
database has recovered, the migration can be performed.

To determine if the database is in a healthy state, we look at the
replication lag of any replication slots defined on the primary. If the
lag is deemed to great (100 MB by default) for too many slots, the
migration is rescheduled for a later point in time.

The health checking code is hidden behind a feature flag, allowing us to
disable it if necessary.