Root container repository is a images repository that had been created
before 9.1, before we introduced multi-level images support.

This regexp is extracted from Docker Distribution 2.4.1 docs, contains
additional `/` element that can be a separator of components.

* master: (230 commits)
  Fix N+1 query in loading pipelines in merge requests
  Fix Spinach and Capybara dependencies
  Prevent users from disconnecting gitlab account from CAS
  30276 Move issue, mr, todos next to profile dropdown in top nav
  Refactor SearchController#show
  Properly eagerly-load the Capybara server for JS feature specs only
  Updating documentation to include a missing step in the update procedure
  Eager-load the Capybara server to prevent timeouts
  Increase Capybara's timeout
  Add metrics button to Environment Overview page
  Fix link to Jira service documentation
  Handle parsing OpenBSD ps output properly to display sidekiq infos on ...
  Eliminate unnecessary queries that add ~500 ms of load time for a large issue
  20914 Limits line length for project home page
  Allow users to import GitHub projects to subgroups
  Update dpl CI example
  Fix the docs:check:links job
  Don't clean up the gitlab-test-fork_bare repo
  Make GitLab use Gitaly for commit_is_ancestor
  Remove unnecessary ORDER BY clause from `forked_to_project_id` subquery
  ...

Use gitaly commit is ancestor

See merge request !9864

Fix N+1 query in loading pipelines in merge requests

See merge request !10363

From Bullet failures in !10263

Fix Spinach and Capybara dependencies

Closes #30347

See merge request !10395

Closes #30347

20914 Limits line length for project home page

Closes #20914

See merge request !10346

Increase Capybara's timeout

Closes #30236

See merge request !10337

Prevent users from disconnecting gitlab account from CAS

Closes #25556

See merge request !10282

Add download attribute to download links

See merge request !10318

30276 Move issue, mr, todos next to profile dropdown in top nav

Closes #30276

See merge request !10347

Updating documentation to include a missing step in the update procedure

See merge request !10373