fix(langfuse): pin clickhouse version to avoid error during clickhouse init

The releases published on 27/03/26 causes Clickhouse to incorrectly
initialize. This prevent the DB from restarting after the initial run.

This pin the version to the most recent version that was working
properly.

Author: GauthierPLM

templates/compose/langfuse.yaml

@@ -119,7 +119,7 @@ services:
       retries: 10
 
   clickhouse:
-    image: clickhouse/clickhouse-server:latest
+    image: clickhouse/clickhouse-server:26.2.4.23
     user: "101:101"
     environment:
       - CLICKHOUSE_DB=${CLICKHOUSE_DB:-default}