In Rails 5.0 headers are no longer inherited from Hash.
This commit fixes errors in requests specs like:

```
1) API::V3::Builds GET /projects/:id/builds/:build_id/artifacts job with artifacts when artifacts are stored locally authorized user returns specific job artifacts
    Failure/Error: expect(response.headers).to include(download_headers)

    NoMethodError:
      undefined method `downcase' for #<Hash:0x000055e8bccc23b0>
    # ./spec/requests/api/v3/builds_spec.rb:235:in `block (6 levels) in <top (required)>'
```

Fix example config miss-alignment in uploads.object_store.connection

Closes gitlab-development-kit#342

See merge request gitlab-org/gitlab-ce!18622

Resolve "Add how to use nip.io to Auto DevOps and Kubernetes documentation"

Closes #45561

See merge request gitlab-org/gitlab-ce!18494

Remove IDE image upload spec

Closes #45045

See merge request gitlab-org/gitlab-ce!18617

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/45045

Remove comma from the time system notes

See merge request gitlab-org/gitlab-ce!18593

Repository#exists? can only be queried with Gitaly

Closes gitaly#314

See merge request gitlab-org/gitlab-ce!18567

Don't run JS lint report for QA

See merge request gitlab-org/gitlab-ce!18621

Add gitlab-pages admin ping rake task

See merge request gitlab-org/gitlab-ce!18372

Skip db related tests for QA

See merge request gitlab-org/gitlab-ce!18618

CE: Fix QA protected branches tests

See merge request gitlab-org/gitlab-ce!18585

and skip db related jobs for QA branches

Fix rubocop offense and enable jobs for qa

See merge request gitlab-org/gitlab-ce!18613

while producing products. Basically an attempt to fix:
https://gitlab.com/gitlab-org/gitlab-qa/-/jobs/65016456

Selenium::WebDriver::Error::StaleElementReferenceError:
  stale element reference: element is not attached to the page document

in:

``` ruby
product :name do
  Page::Project::Settings::Repository.act do
    expand_protected_branches(&:last_branch_name)
  end
end
```

Fixed typos

See merge request gitlab-org/gitlab-ce!18432

We could revisit which we don't want to run in qa.

CE Backport: Reveal labels dropdown when labels icon is clicked on collapsed Epic sidebar

See merge request gitlab-org/gitlab-ce!18611

Add more QA SSH key tests

Closes gitlab-qa#183

See merge request gitlab-org/gitlab-ce!17662

Clear refresh interval when MRWidgetFailedToMerge component is destroyed

See merge request gitlab-org/gitlab-ce!18600

Reset milestone filter when clicking "Any Milestone" in dashboard

Closes #45295

See merge request gitlab-org/gitlab-ce!18531

Remove `peek-performance_bar` from the performance bar

See merge request gitlab-org/gitlab-ce!18597

Rename the Edge label to Quality

See merge request gitlab-org/gitlab-ce!18457

Delete object_state_models.md

See merge request gitlab-org/gitlab-ce!18588

Fix calendar day position

See merge request gitlab-org/gitlab-ce!18516

Restore size and position for fork icon

See merge request gitlab-org/gitlab-ce!18449

Fixed bugs with IDE new directory

Closes #44838

See merge request gitlab-org/gitlab-ce!18274

Merge branch '45451-user-deletion-modal-with-same-info-for-delete-user-or-delete-user-and-contributions' into 'master'

Resolve "User deletion modal with same info for delete user / delete user and contributions"

Closes #45451

See merge request gitlab-org/gitlab-ce!18463