Revise 2.52 upgrade notes for Valkey integration

Updated documentation for version 2.52 to reflect the transition from Redis to Valkey as the message broker, including UI fixes and deduplication improvements.

Author: valentijnscholten

docs/content/en/open_source/upgrading/2.52.md

@@ -5,7 +5,6 @@ weight: -20251006
 description: Replaced Redis with Valkey & Helm chart changes & MobSF parser merge
 ---
 
-## Valkey
 ## Fix UI overwriting service field from parsers
 
 The web form in the UI by default sends an empty string, which ended up overwriting the service value provided by parsers.
@@ -24,7 +23,7 @@ See [PR 13517](https://github.com/DefectDojo/django-DefectDojo/pull/13517) for m
 A bug was fixed in the `UNIQUE_ID_OR_HASH_CODE` algorithm where it stopped processing candidate findings with equal `unique_id_from_tool` or `hash_code` value.
 Strictly speaking this is not a breaking change, but we wanted to make you aware that you can see more (better) more deduplicatation for parsers using this algorithm.
 
-## Merge of MobSF parsers
+## Valkey in `docker compose`
 
 Since the license change at Redis the fork ValKey has become widely popular and is backed by industry giants such as AWS. AWS is advising to use ValKey over Redis and is using lower prices for ValKey compared to Redis.