Enable cache to configure for Redis Cluster

What does this MR do?

This MR enables cache to be configured for Redis Cluster. The cache support was added in 16.1 (gitlab!120251 (merged)).

No corresponding charts MR is needed as charts does not impose any restrictions like in omnibus.

Related issues

gitlab-com/gl-infra/scalability#2350 (closed)

This MR unblocks a CR -- gitlab-com/gl-infra/production#16100 (comment 1499033300)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• MR title and description are up to date, accurate, and descriptive.
• MR targeting the appropriate branch.
• Latest Merge Result pipeline is green.
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow.

For GitLab team members

If you don't have access to this, the reviewer should trigger these jobs for you during the review process.

• The manual Trigger:ee-package jobs have a green pipeline running against latest commit.
• If config/software or config/patches directories are changed, make sure the build-package-on-all-os job within the Trigger:ee-package downstream pipeline succeeded.
• If you are changing anything SSL related, then the Trigger:package:fips manual job within the Trigger:ee-package downstream pipeline must succeed.
• If CI configuration is changed, the branch must be pushed to dev.gitlab.org to confirm regular branch builds aren't broken.

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes.
• Documentation created/updated. - redis cluster is still used by .com so far, we will release docs when the application is entirely cluster compatible and we have sufficient operational expertise to advise SM users on this topic.
• Tests added. - test updated since we are adding values into an allow-list
• Integration tests added to GitLab QA. -- N.A.
• Equivalent MR/issue for the GitLab Chart opened. -- charts does not enforce allowlist for cluster
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file. -- N.A.