[FLINK-36059][tests] Bump cp-kafka and cp-schema-registry from 7.2.2 to 7.2.9

cp-kafka:7.2.2 ships JDK 11.0.16.1 which has a known cgroup v2 bug (JDK-8287073) that causes a NullPointerException in CgroupV2Subsystem.getInstance(). Docker 29 changed cgroup handling in a way that now triggers this bug, crashing the Kafka container before it can start and failing SqlClientITCase.

cp-kafka:7.2.9 ships JDK 11.0.21 which includes the fix. Update cp-schema-registry to 7.2.9 as well since it bundles the same vulnerable JDK.
(cherry picked from commit 2db7996)

Author: MartijnVisser

flink-end-to-end-tests/test-scripts/test_confluent_schema_registry.sh

@@ -20,7 +20,7 @@
 set -Eeuo pipefail
 
 KAFKA_VERSION="3.2.3"
-CONFLUENT_VERSION="7.2.2"
+CONFLUENT_VERSION="7.2.9"
 CONFLUENT_MAJOR_VERSION="7.2"
 # Check the Confluent Platform <> Apache Kafka compatibility matrix when updating KAFKA_VERSION
 KAFKA_SQL_VERSION="universal"

flink-end-to-end-tests/test-scripts/test_pyflink.sh

@@ -20,7 +20,7 @@
 set -Eeuo pipefail
 
 KAFKA_VERSION="3.2.3"
-CONFLUENT_VERSION="7.2.2"
+CONFLUENT_VERSION="7.2.9"
 CONFLUENT_MAJOR_VERSION="7.2"
 # Check the Confluent Platform <> Apache Kafka compatibility matrix when updating KAFKA_VERSION
 KAFKA_SQL_VERSION="universal"

flink-test-utils-parent/flink-test-utils-junit/src/main/java/org/apache/flink/util/DockerImageVersions.java

@@ -28,9 +28,9 @@
  */
 public class DockerImageVersions {
 
-    public static final String KAFKA = "confluentinc/cp-kafka:7.2.2";
+    public static final String KAFKA = "confluentinc/cp-kafka:7.2.9";
 
-    public static final String SCHEMA_REGISTRY = "confluentinc/cp-schema-registry:7.2.2";
+    public static final String SCHEMA_REGISTRY = "confluentinc/cp-schema-registry:7.2.9";
 
     public static final String KINESALITE = "instructure/kinesalite:latest";