- Migration updates existing groups to "owner", then sets default to
  "maintainer" so that new groups will default to that
- Update spec examples

Both with subgroup_creation_level set to owners and to maintainers.
Also fixed the naming of some other examples in the same spec as they
were contradicting what they were actually performing in the test.
These examples were probably copy/pasted, and not renamed.

For both groups_controller and admin/groups_controller

This setting is at the group level only. The default is specified to
be maintainers and owners.

**Specs only**, all failing.

All specs passing

- Change the two existing feature examples that create a subgroup to
  elucidate that the owner is creating the subgroup

- Nest two more specs inside the 'subgroup support' context detailing
  what happens when a maintainer attempts to add a subgroup (one with
  subgroup support, and one without)

Fix Gitaly auto-detection caching

Closes #64802

See merge request gitlab-org/gitlab-ce!30954

Remove duplicate buttons

Closes #64160

See merge request gitlab-org/gitlab-ce!30757

Document database review process

See merge request gitlab-org/gitlab-ce!30405

See https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6069

Get rid of `worker_label` in RubySampler

See merge request gitlab-org/gitlab-ce!30942

Avoid increasing redis counters when usage_ping is disabled

See merge request gitlab-org/gitlab-ce!30949

If `GitalyClient#can_use_disk?` returned `false`, it was never cached
properly and led to excessive number of Gitaly calls. Instead of using
`cached_value.present?`, we need to check `cached_value.nil?`.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/64802

Fixes the alignment on reports

See merge request gitlab-org/gitlab-ce!30839

- Removes a justify-center class that causes reports to centrally align

Centers loading icon in CI action

Closes #64265

See merge request gitlab-org/gitlab-ce!30947

Use `issuable_path` helper

See merge request gitlab-org/gitlab-ce!30913

Resolve "Export frontend fixtures as pipeline artifact"

Closes #64722 and #59166

See merge request gitlab-org/gitlab-ce!30917