Clarify Dedicated Cloud Gateways builtin Redis capabilities

[jbaross]

Jobs to be done

Based on https://app.kapa.ai/93b55f65-cffb-4d0b-9da7-c8915a838dce/conversations/c85bc4aa-3adb-4ad7-bbde-752eb6714529, determine if the builtin Redis supports vector DB functionality and can be used by AI Gateway semantic policies

This may not be applicable in the 2.0 world depending on how Gateway and AI Gateway do or do not integrate.

Definition of done

Update https://app.kapa.ai/93b55f65-cffb-4d0b-9da7-c8915a838dce/conversations/c85bc4aa-3adb-4ad7-bbde-752eb6714529

Due date (optional)

Size

• S (Small). Example: fixing a broken link, updating wording in an FAQ or paragraph