* Upgrade dependencies whenever it is reasonable
* Fix deprecations and some new API paths
* Move docs to a new version with respective branching for the `changes-5.5-6.0.adoc`
* Add `--add-opens` to `asciidoctor` Gradle task to avoid compilation warning
* Upgrade to Kotlin `1.6.10` and modify its Gradle task respective
* Add empty impl for new `AnnotationMetadataAdapter.getDeclaredMethods()`
* Parse HTTP methods to new `String methodNames` property of the `RequestMapping`
since `HttpMethod` is not an `enum` anymore.
* Ignore JDBC tests which rely on a map property resolution: the `[]` placeholder
is not handled in the latest SF anymore.
* Fix `WebFluxInboundEndpoint` for deprecations
* Upgrade to Java 17, SF-6.0, Gradle 7.2
* Upgrade to Jakarta dependencies and respective namespaces
* Fix some tests for Java 17 compatibility
* Fix wrong Javadocs
* Add some missed Javadocs
* Fix more `jakarta` namespace
* Fix WS & XML modules to use Jakarta EE
* `--add-opens` in some modules for their reflection-based tests
* Disable Kafka tests which does not work on Windows; see Apache Kafka `3.0.1`
* Upgrade to JUnit `5.8.1`
* Migrate JMS tests to Artemis
* Remove RMI module as it was deprecated before
* Fix `pr-build-workflow.yml` for Java 17
* Fix JavaDocs warnings using `Xdoclint:syntax` per module, not in the top-level `api` task
* Move docs for version `6.0`
Rework the logic around `ManagedList` in the `DefaultConfiguringBeanFactoryPostProcessor`
when it registers a `IntegrationContextUtils.MESSAGE_HANDLER_FACTORY_BEAN_NAME` and
`IntegrationContextUtils.LIST_MESSAGE_HANDLER_FACTORY_BEAN_NAME` into a dedicated
`MessageHandlerMethodFactoryCreatingFactoryBean` with pure Java code instead of
`BeanDefinition` burden
* Deprecate `IntegrationContextUtils.DISPOSABLES_BEAN_NAME` constant for
already removed internal bean
* Align JVM args for Gradle with Java 17 on the `6.0` branch
Resolves https://github.com/spring-projects/spring-integration/issues/3600
Previously, the `KafkaProducerMessageHandler` did not synchronize a transaction
with some other transaction (e.g. JDBC); it published in a local transaction instead.
Also configure the Gradle Kotlin Daemon to work with JDK 16.
**cherry-pick to 5.4.x**
