The spec is too strict about how many `current_version` should be
called - if the spec is called separately, it's called 3 times, if
all specs run it's called twice.

This is similar to the change done in
9b752791624ce618810b9d65251582e56c37dee7

Step 1 of !28996: Adds models and migrations for Namespaces statistics

See merge request gitlab-org/gitlab-ce!29570

- Namespace::Storagestatistics will persist root namespace statistics
- Namespace::AggregationSchedule will save information when a new update
to the namespace statistics needs to be scheduled

Both tables use 'namespace_id' as primary key

When a user sets only_allow_merge_if_pipeline_succeeds, also named
as "Pipeline must succeed" project setting, we require the pipeline
to be present.

This solves race condition issues especially with external CI
providers when a build is triggered externally but no pipelines are
created in GitLab yet.

Document that a head pipeline is expected when using "Pipeline
must succeed" setting. Also explain limitations with the use of
only/except where there may not be any jobs created and the merge
request will not be allowed to be merged.

Refactor Deployment#cluster to #deployment_platform_cluster

See merge request gitlab-org/gitlab-ce!29961

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

Fix label serialisation in issue and note hooks

Closes #63473

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

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

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