The main sticking point was `config/README.md`, which went into a lot of
detail about each instance. It was quite easy to make a copy and paste
error, as some instances had default URLs and others didn't, some had
fallback instances and others didn't, etc.

This changes a number of things:

1. `config/README.md` now has a table for the Redis instances with a
   single list of instructions that apply to all instances.
2. There are now specs to ensure that each Redis instance has a default
   URL set when no Redis config at all is present.
3. Instances that use a fallback instance for config will automatically
   use the default URL of their fallback instance. They should not
   define their own default URL.
4. The `.gitignore` file does not need to be updated for each new Redis
   instance.
5. The example config files are now gone as `request.yml.example` should
   be sufficient.

This instance is not used yet, but will soon be used for rate limiting
via Rack::Attack and Gitlab::ApplicationRateLimiter. Having this
configuration option in place will allow us to build on that, and also
create merge requests to support this option in Omnibus and our Helm
charts.

Doc Consistency: integration - access

See merge request gitlab-org/gitlab!71143

Doc Consistency: integration - integrations (Part 2)

See merge request gitlab-org/gitlab!71147

Doc Consistency: integration - integrations

See merge request gitlab-org/gitlab!71145

Vale issues administration pages

See merge request gitlab-org/gitlab!71141

E2E: Large project github import test debug improvements

See merge request gitlab-org/gitlab!70910

Handle HTTP 429 status gracefully

See merge request gitlab-org/gitlab!71182

Update screenshots of license policy

See merge request gitlab-org/gitlab!71245

Add suggestion to use match_array instead of match for array expectation

See merge request gitlab-org/gitlab!64313

Add false-positive information in the api response

See merge request gitlab-org/gitlab!70328

Change incorrect exception wording modifying

See merge request gitlab-org/gitlab!71240

Shrink cross-db spec allowlist

See merge request gitlab-org/gitlab!71123

Remove usage of extend from table SCSS

See merge request gitlab-org/gitlab!70897

The word modifying is not correct for this as these queries are not
necessarily "modifying" anything. I think querying is more accurate.

feat: fix doc warnings by Vale acronym rule

See merge request gitlab-org/gitlab!71106

Add connection fallback to ActiveRecordProxy

See merge request gitlab-org/gitlab!71059

Fix post merge CI status bug [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!70719

Add report_type into approval_project_rules

See merge request gitlab-org/gitlab!70221

Fixed bug where users see error message
on post merge pipeline due to incorrect
handling of ciStatus.

Changelog: fixed

Remove usage_data_i_testing_group_code_coverage_visit_total feature flag

See merge request gitlab-org/gitlab!70950

Remove feature flag `ci_minutes_track_live_consumption`

See merge request gitlab-org/gitlab!71072

Remove feature flag check for candece finder

See merge request gitlab-org/gitlab!71192

Drop old int4 PK column for push_event_payloads

See merge request gitlab-org/gitlab!70920

Rename error tracking api files

See merge request gitlab-org/gitlab!70939

Remove OpenProjectTrackerData model and spec

See merge request gitlab-org/gitlab!70294

Removed OpenProjectTrackerData model and spec since
we're reverting the changes made for the OpenProject
integration

Extend EE::Types::Ci::PipelineType with dast_profile

See merge request gitlab-org/gitlab!69808