Add jackson-databind to AMQP module for tests

The latest changes in Spring AMQP about migrating from RabbitMQ Hop
project to WebFlux has lead to dropping a Jackson deps which were
before transitive from Hop

* Add `com.fasterxml.jackson.core:jackson-databind` as tests dependency into AMQP module

build.gradle

@@ -481,6 +481,7 @@ project('spring-integration-amqp') {
         testImplementation project(':spring-integration-stream')
         testImplementation 'org.springframework:spring-web'
         testImplementation 'org.testcontainers:rabbitmq'
+        testImplementation 'com.fasterxml.jackson.core:jackson-databind'
     }
 }