Fix ChromaVectorStoreAutoConfigurationIT configuration

Author: tzolov

spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/vectorstore/chroma/ChromaVectorStoreAutoConfigurationIT.java

@@ -23,6 +23,8 @@
 import org.testcontainers.junit.jupiter.Container;
 import org.testcontainers.junit.jupiter.Testcontainers;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 import io.micrometer.observation.tck.TestObservationRegistry;
 import io.micrometer.observation.tck.TestObservationRegistryAssert;
 
@@ -148,6 +150,11 @@ public EmbeddingModel embeddingModel() {
 			return new TransformersEmbeddingModel();
 		}
 
+		@Bean
+		public ObjectMapper objectMapper() {
+			return new ObjectMapper();
+		}
+
 	}
 
 }