Description

This PR removes previously-deprecated fields that were named specifically for Redis and cleans up a few other references (such as valid engine types for Managed Database plans). All services have been converted from Redis to Valkey, so the new, more generic-named fields should be used going forward.

Checklist:

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you linted your code locally prior to submission?
• Have you successfully ran tests with your changes locally?