Update mongo docker image version (#13829)

Author: laurit

instrumentation/mongo/mongo-common/testing/src/main/java/io/opentelemetry/instrumentation/mongo/testing/AbstractMongoClientTest.java

@@ -52,7 +52,7 @@ public abstract class AbstractMongoClientTest<T> {
   @BeforeAll
   void setup() {
     mongodb =
-        new GenericContainer<>("mongo:4.0")
+        new GenericContainer<>("mongo:4.2")
             .withExposedPorts(27017)
             .withLogConsumer(new Slf4jLogConsumer(LoggerFactory.getLogger("mongodb")));
     mongodb.start();