nixos/apache-kafka: remove ZooKeeper option

nixos/modules/services/misc/apache-kafka.nix

@@ -63,7 +63,7 @@ in
 
         options = {
           "broker.id" = lib.mkOption {
-            description = "Broker ID. -1 or null to auto-allocate in zookeeper mode.";
+            description = "Broker ID.";
             default = null;
             type = with lib.types; nullOr int;
           };
@@ -172,9 +172,13 @@ in
       [ "services" "apache-kafka" "logDirs" ]
       [ "services" "apache-kafka" "settings" "log.dirs" ]
     )
-    (lib.mkRenamedOptionModule
-      [ "services" "apache-kafka" "zookeeper" ]
-      [ "services" "apache-kafka" "settings" "zookeeper.connect" ]
+    (lib.mkRemovedOptionModule
+      [
+        "services"
+        "apache-kafka"
+        "zookeeper"
+      ]
+      "ZooKeeper mode is no longer supported by any packaged Apache Kafka version; please migrate to KRaft mode instead"
     )
 
     (lib.mkRemovedOptionModule [

nixos/modules/services/misc/kafka.md

@@ -12,10 +12,9 @@ manual](https://kafka.apache.org/documentation/#configuration) broker settings.
 
 ## KRaft {#module-services-apache-kafka-kraft}
 
-Unlike in Zookeeper mode, Kafka in
-[KRaft](https://kafka.apache.org/documentation/#kraft) mode requires each log
-dir to be "formatted" (which means a cluster-specific a metadata file must
-exist in each log dir)
+Kafka in [KRaft](https://kafka.apache.org/documentation/#kraft) mode requires
+each log dir to be "formatted" (which means a cluster-specific a metadata file
+must exist in each log dir)
 
 The upstream intention is for users to execute the [storage
 tool](https://kafka.apache.org/documentation/#kraft_storage) to achieve this,
@@ -59,5 +58,4 @@ Notable changes to be aware of include:
   - [Upstream docs](https://kafka.apache.org/documentation.html#brokerconfigs_broker.id)
 
 - Removal of `services.apache-kafka.zookeeper`
-  - Translate using: `services.apache-kafka.settings."zookeeper.connect"`
-  - [Upstream docs](https://kafka.apache.org/documentation.html#brokerconfigs_zookeeper.connect)
+  - ZooKeeper mode is no longer supported; migrate to [KRaft](#module-services-apache-kafka-kraft) mode instead.