test(kafka): ensure ProducerSystemTest can connect to kafka

Without, the test connects to a kafka instance of a previous spring context instance - which is an embeddedkafka and not available

springwolf-examples/springwolf-kafka-example/src/test/java/io/github/stavshamir/springwolf/example/kafka/ProducerSystemTest.java

@@ -15,7 +15,7 @@
 import org.springframework.boot.ssl.DefaultSslBundleRegistry;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.mock.mockito.SpyBean;
-import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.TestPropertySource;
 import org.testcontainers.containers.DockerComposeContainer;
 import org.testcontainers.junit.jupiter.Container;
 import org.testcontainers.junit.jupiter.Testcontainers;
@@ -39,7 +39,7 @@
         classes = {SpringwolfKafkaExampleApplication.class},
         webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 @Testcontainers
-@DirtiesContext
+@TestPropertySource(properties = {"spring.kafka.bootstrap-servers=localhost:9092"})
 @TestMethodOrder(OrderAnnotation.class)
 // @Ignore("Uncomment this line if you have issues running this test on your local machine.")
 public class ProducerSystemTest {