chore: Bump zookeeper version for 25.11.0 (#894)

Author: xeniape

docs/modules/kafka/examples/getting_started/zookeeper.yaml

@@ -5,7 +5,7 @@ metadata:
   name: simple-zk
 spec:
   image:
-    productVersion: 3.9.3
+    productVersion: 3.9.4
   servers:
     roleGroups:
       default:

tests/test-definition.yaml

@@ -25,9 +25,10 @@ dimensions:
   - name: zookeeper
     values:
       - 3.9.3
+      - 3.9.4
   - name: zookeeper-latest
     values:
-      - 3.9.3
+      - 3.9.4
   - name: upgrade_old
     values:
       - 3.7.2