Resolve "Filter by `None`/`Any` for labels in issues/mrs API"

Closes #52371

See merge request gitlab-org/gitlab-ce!22622

Add docs note for Reverting MR availability

See merge request gitlab-org/gitlab-ce!22289

add a note about omnibus chart and info how to backup with gitlab chart

See merge request gitlab-org/gitlab-ce!23097

CE port: Promote the GitLab.com Gold trial on a users default dashboard

See merge request gitlab-org/gitlab-ce!22901

[docs] Enable importing from other sites

See merge request gitlab-org/gitlab-ce!23082

Set content disposition attachment to several endpoints

See merge request gitlab-org/gitlab-ce!23223

Add instructions on how to add Prometheus as data source in Grafana

See merge request gitlab-org/gitlab-ce!23273

Replace public_jobs attribute with public_builds attribute in Projects API docs

See merge request gitlab-org/gitlab-ce!23194

Add missing languages in Proofreaders page

See merge request gitlab-org/gitlab-ce!23243

Deploy cert-manager to managed cluster for SSL certificates

See merge request gitlab-org/gitlab-ce!23036

Refactor landing page CE

See merge request gitlab-org/gitlab-ce!23215

By using the parameters `?labels=None|Any` the user can filter
issues/mrs from the API that has `none/any` label.

Affected endpoints are:

- /api/issues
- /api/projects/:id/issues
- /api/groups/:id/issues
- /api/merge_requests
- /api/projects/:id/merge_requests
- /api/groups/:id/merge_requests

Fix 404ing links for NGINX ingress controller

See merge request gitlab-org/gitlab-ce!23258

Move links to HTTPS to avoid possible 503 errors in broken link checkers

See merge request gitlab-org/gitlab-ce!23313

refresh the path to performance bar in admin settings with the up-to-date value

See merge request gitlab-org/gitlab-ce!23316

update screenshot for request profiling token

See merge request gitlab-org/gitlab-ce!23317

Delete Research proposal.md

See merge request gitlab-org/gitlab-ce!23322

Clean up fix for RegisterJobService

See merge request gitlab-org/gitlab-ce!23315

Resolve "Improve issues list empty state when a filter is selected"

Closes #53326

See merge request gitlab-org/gitlab-ce!22775

Explicitly set locale fallbacks

Closes #54274

See merge request gitlab-org/gitlab-ce!23271

Rails5 deprecation: :nothing option is deprecated, Use head method to respond with empty response body.

See merge request gitlab-org/gitlab-ce!23311

Correctly styles tags in jobs sidebar

Closes #54391

See merge request gitlab-org/gitlab-ce!23319

The tags were using the `label` class
instead of `bagde` which is the new BS class

Allow commenting to resolved non-diff discussions

Closes #54330

See merge request gitlab-org/gitlab-ce!23279

Add support for custom highlighting slash commands via warning flags

See merge request gitlab-org/gitlab-ce!23277

Rails5: env is deprecated and will be removed from Rails 5.1

Closes #54384

See merge request gitlab-org/gitlab-ce!22626

Prefer `each` to `find` since the former does the same thing
except doesn't add the extra delegation step that may be causing
the binding_of_caller gem issues.

Relates to https://gitlab.com/gitlab-org/gitlab-ce/issues/54281#note_119494004