This makes things simpler as no scheduling is involved. Further we
remove the need for running a SELECT + UPDATE just to get the key and
update it, whereas we only need an UPDATE when setting last_used_at
directly in a request.

The added service class takes care of updating Key#last_used_at without
using Sidekiq. Further it makes sure we only try to obtain a Redis lease
if we're confident that we actually need to do so, instead of always
obtaining it. We also make sure to _only_ update last_used_at instead of
also updating updated_at.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36663

The default scope in Event would add a "WHERE author_id IS NOT NULL"
clause to every query. Now that "events.author_id" has a NOT NULL clause
set this filter is redundant and we can safely remove it.

In this commit we also add a validation on events.author_id (previously
only defined in PushEvent) just in case something tries to create data
without an author ID. This way we can present a nicer error message
compared to PostgreSQL's foreign key error messages.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/38129

* Will dry up the code to find projects between the ForksController and the API

And link to it from where you change your username.

And expand on the help text.

Displays the Gitaly version in the admin dashboard.

This ensures the open issues/MR count caches are refreshed properly when
creating new issues or MRs. This MR also includes a change to the cache
keys to ensure all caches are rebuilt on the fly.

This particular problem was not caught in the test suite due to a null
cache being used, resulting in all calls that would use a cache using
the underlying data directly. In production the code would fail because
a newly saved record returns an empty hash in #changes meaning checks
such as `state_changed? || confidential_changed?` would return false for
new rows, thus never updating the counters.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/38061

Instead perform soft check (the column set to indicate that file does exist)

We recently started adding YAML frontmatter in docs so that we can
show more information, but that only works for the docs portal at
docs.gitlab.com.

For example, we want to add a last_updated entry
https://gitlab.com/gitlab-org/gitlab-ce/issues/37677

Whereas this is useful for the docs portal, it looks ugly for docs
under /help.

Discussions are now done asynchronously via the `IssuesController#discussions`
endpoint, so this should no longer be needed. This was taking 32% of the load
time for GitLab CE issue 1.

Closes #38034

Closes #37972

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/33287

The MR widget was trying to render the pipelines section when
there are no GitLab CI pipelines which was throwing some NPE
errors.