chore: mark Kafka 4.2.1 as deprecated (#1047)

Author: razvan

CHANGELOG.md

@@ -74,7 +74,7 @@ All notable changes to this project will be documented in this file.
   shipped in the same product image as `kafka` since #527, so the dedicated container/image was
   no longer needed). The `kcat-prober` value is no longer accepted in a broker's
   `logging.containers` CRD field ([#1010]).
-- Support for Kafka 4.1.1 and 4.2.1 ([#1022])
+- Support for Kafka 4.1.1 and 4.2.1 (deprecated) ([#1022], [#1047])
 
 [#985]: https://github.com/stackabletech/kafka-operator/pull/985
 [#990]: https://github.com/stackabletech/kafka-operator/pull/990
@@ -96,6 +96,7 @@ All notable changes to this project will be documented in this file.
 [#1043]: https://github.com/stackabletech/kafka-operator/pull/1043
 [#1044]: https://github.com/stackabletech/kafka-operator/pull/1044
 [#1046]: https://github.com/stackabletech/kafka-operator/pull/1046
+[#1047]: https://github.com/stackabletech/kafka-operator/pull/1047
 
 ## [26.7.0] - 2026-07-21
 

docs/modules/kafka/partials/supported-versions.adoc

@@ -3,7 +3,7 @@
 // Stackable Platform documentation.
 
 * 4.3.1
-* 4.2.1
+* 4.2.1 (deprecated)
 * 3.9.2 (LTS)
 
 Starting with Apache Kafka 4, the quorum manager has been changed from Apache Zookeeper to the built-in KRaft.