CE backport for changes in EE MR 14646

See merge request gitlab-org/gitlab-ce!30932

This commit covers all the files that where changed in the
identically named branch on EE that is creating an elasticsearch
test case.

Ignore Gitaly errors if cache flushing fails on project destruction

See merge request gitlab-org/gitlab-ce!31164

Update jenkins.md - add CTA to about.gitlab page

See merge request gitlab-org/gitlab-ce!31259

We should just ignore these errors and move along with the deletion
since the repositories are going to be trashed anyway.

Closes https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/31164

documentation: fix a typo in ci/examples

See merge request gitlab-org/gitlab-ce!31250

Raise /gitlab-basics to SSoT Docs standards

Closes #65153

See merge request gitlab-org/gitlab-ce!31172

Removes duplicated information, and combines sections and files
together when they are duplicated or highly related. Also adds
intros to all pages and sections missing intros, and troubleshooting
sections to pages that may need them in the future. Links more to
other docs, and clarifies language when abosolutely necessary, and
adds angle brackets to sample parameters.

Add retry on exception to mattermost login spec

See merge request gitlab-org/gitlab-ce!31243

Correct manual sort introduction release

See merge request gitlab-org/gitlab-ce!31135

Add gradle to not-yet-supported list

Closes gitlab-ee#12393

See merge request gitlab-org/gitlab-ce!31228

Update visibility level docs

See merge request gitlab-org/gitlab-ce!31258

Have deterministic DNS for specs

See merge request gitlab-org/gitlab-ce!31086

Add requesting particular OAuth2 scopes details

Closes #65200

See merge request gitlab-org/gitlab-ce!31215

Document Code Quality potential security flaw

Closes #37980

See merge request gitlab-org/gitlab-ce!31197

Adds troubleshooting guidance to SAML SCIM setup docs

See merge request gitlab-org/gitlab-ce!28921

Update rouge to v3.7.0

Closes #64625

See merge request gitlab-org/gitlab-ce!31254

Changes to Repository docs for SSOT epic

See merge request gitlab-org/gitlab-ce!31075

Content about Repository was edited to comply with
docs standards. This is part of a SSOT epic.

- Added standard elements to each file.
- Moved content on Branches, and Compare, to the
  Branches file.
- Added a brief introduction piece to the GPG
  content.
- Lightly edited all content to improve clarity.

Merge branch '63547-add-system-notes-for-when-a-zoom-call-was-added-removed-from-an-issue' into 'master'

Resolve "Add system notes for when a zoom call was added/removed from an issue"

Closes #63547

See merge request gitlab-org/gitlab-ce!30857

Reorganize metrics dashboard

See merge request gitlab-org/gitlab-ce!31006

In preparation for embedding specific metrics in issues
https://gitlab.com/gitlab-org/gitlab-ce/issues/62971,
this commit moves the BaseService for metrics dashboards
to a new services subdirectory. This is purely for the sake
of organization and maintainability.

This adds support for a number of new languages (e.g. Ada)
and fixes a number of lexers:
https://github.com/rouge-ruby/rouge/compare/v3.5.1..v3.7.0

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/64625

Resolve "Make quick action "commands applied" banner more useful"

Closes #56100

See merge request gitlab-org/gitlab-ce!26672

Extends the quick actions "commands applied" banner to show
the quick action preview text, but with everything in past tense.

Resolve "MembersFinder contains slow database query with OR conditions"

Closes #64180

See merge request gitlab-org/gitlab-ce!30451

Otherwise certain machines return IPv6 first, which is non-deterministic

Rather than relying on NoMethodError deep inside faraday

This means we have one less Net::HTTP monkeypatch.

sham_rack cannot handle IPv6 addresses which means it breaks Net::HTTP
connections because it monkey-patches Net::HTTP

Alerts dropdown to modal - CE1

See merge request gitlab-org/gitlab-ce!31036

Adding parenthetical about guest users not being able to view private
projects.

Fix broken master because of security merge

Closes #65294

See merge request gitlab-org/gitlab-ce!31252

Update Rugged to 0.28.2

See merge request gitlab-org/gitlab-ce!31218

Add a zoom link added / removed system note when a zoom link is being
added / removed to the issue description.