Add missing containers configuration reference to code snippet

See gh-35031

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/features/testing/testcontainers/atdevelopmenttime/test/TestMyApplication.java

@@ -21,7 +21,7 @@ import org.springframework.boot.SpringApplication;
 public class TestMyApplication {
 
 	public static void main(String[] args) {
-		SpringApplication.from(MyApplication::main).run(args);
+		SpringApplication.from(MyApplication::main).with(MyContainersConfiguration.class).run(args);
 	}
 
 }