Speed up used languages calculation on charts page

See merge request !12212

set ENV['prometheus_multiproc_dir'] in config/boot.rb instead of config.ru

See merge request !12201

We removed calls from our code to Rugged::Repository#fetch_attributes:
<https://gitlab.com/gitlab-org/gitlab_git/commit/340e111e040ae847b614d35b4d3173ec48329015>

However, we didn't remove calls from within Linguist. This method is only called
when calculating the languages for a repository on the Charts page:
<https://github.com/github/linguist/blob/v4.7.0/lib/linguist/lazy_blob.rb#L33-L36>

We can safely use our own Gitlab::Git::Attributes here. On staging, for the
GitLab CE repo, this makes the calculation take about a third of the time:

    # Before
    Benchmark.realtime do
      Linguist::Repository.new(repository.rugged,
                               repository.rugged.head.target_id).languages
    end
    #=> 23.67193900188431

    # After
    Benchmark.realtime do
      Linguist::Repository.new(repository.rugged,
                               repository.rugged.head.target_id).languages
    end
    #=> 8.945212290156633

Wait for all Ajax and Vue requests to complete in JavaScript tests

Closes #33756

See merge request !12203

Convdev docs

See merge request !12189

Clarify job selection algorithm docs

See merge request !12199

Use the same way to invalidate cache from EE

See merge request !12187

Expose correct path to group

See merge request !12176

Fix intermittent spec failures in spec/finders/pipelines_finder_spec.rb

See merge request !12207

[ci skip]

Replace PhantomJS with Chrome in Karma test runner (2nd attempt)

Closes #33633

See merge request !12144

Issue board docs

See merge request !12197

Jira integ docs

See merge request !12196

Confidential issues redesign docs

See merge request !12195

The spec was trying to sort pipelines by user ID, but the same user ID
was being used for each pipeline in the spec. This is similar to #33001.

From logs in #33756, we that it's possible for an Ajax call to be made
before the middleware receives it. To prevent stray Ajax calls from
breaking other specs, we need to wait for all scheduled calls to finish.

Closes #33756

Update ruby metrics endpoint text to be clearer

See merge request !12157

Unify email layouts: devise emails

See merge request !10483

Support a configurable Rails asset_host to allow for CDNs

See merge request !12102

Add a link to spec/migrations/README.md in the testing documentation

See merge request !12191

[ci skip]

Deserialize custom notifications

Closes #24892

See merge request !12055

Try to use the same pattern as other spec in this file

Closes #33614

See merge request !12192

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

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

Service hostname also include registry name, when using non Docker Hub registry.

See merge request !11729