Fix pulsar functions threaded integration tests (#8118)

Co-authored-by: Jerry Peng <jerryp@splunk.com>
diff --git a/tests/integration/src/test/java/org/apache/pulsar/tests/integration/topologies/PulsarCluster.java b/tests/integration/src/test/java/org/apache/pulsar/tests/integration/topologies/PulsarCluster.java
index 36175a6..db77ae6 100644
--- a/tests/integration/src/test/java/org/apache/pulsar/tests/integration/topologies/PulsarCluster.java
+++ b/tests/integration/src/test/java/org/apache/pulsar/tests/integration/topologies/PulsarCluster.java
@@ -417,7 +417,8 @@
                 .withEnv("PF_pulsarFunctionsCluster", clusterName)
                 .withEnv("PF_pulsarServiceUrl", serviceUrl)
                 .withEnv("PF_pulsarWebServiceUrl", httpServiceUrl)
-                .withEnv("PF_threadContainerFactory_threadGroupName", "pf-container-group")
+                .withEnv("PF_functionRuntimeFactoryClassName", "org.apache.pulsar.functions.runtime.thread.ThreadRuntimeFactory")
+                .withEnv("PF_functionRuntimeFactoryConfigs_threadGroupName", "pf-container-group")
                 // script
                 .withEnv("clusterName", clusterName)
                 .withEnv("zookeeperServers", ZKContainer.NAME)