v6.1.0-RC1

Change log:

91fca72 Remove trailing space in IntWebSocketContainer
0391bed Upgrade to json-path-2.8.0
1a579a6 GH-8600: Fix WebSocket removeRegistration (#8601)
934e90a Revert json-path & Mockito versions
dd53de8 Bring back Kotlin version 1.8.10
fe1a3ee Upgrade some dependencies
8dd1332 Fix NPEs in DSL Specs (#8597)
feb4705 Improve Java DSL for Rabbit Streams (#8598)
fa178c3 Fix new Sonar smells
869c5c7 Fix new Sonar smells
d5181bf Add Nullability support into Java DSL
053cc00 GH-3557: Add maxDepth, dirPredicate to FileReadMS (#8596)
aaaa489 (GH-3634) Optimize MessageTriggerAction for Java DSL (#8595)
b997295 GH-8586: Deprecate IntegrationComponentSpec.get() (#8594)
bbaffb2 Fix Checkstyle violations
bbbfc47 Use StandardEvalCtx in the ZeroMqMessageHandler
e69285a Fix sample image link in the amqp.adoc
e03d125 Improve some tests performance
4f5250b Propagate Reactor context over headers (#8591)
6dcdfa8 Fix typo in the configuration.adoc
bfc6931 GH-3869: Add ContextHolderRequestHandlerAdvice
b0093ef TestXmlAppCtxHelper: Fix trailing white space
63937ab Migrate XML module tests to JUnit 5
e39449b (GH-8582) GH-8582: Add TX support for PostgresSubChannel
b326225 Fix tests for replyTimeout
8f83be2 Move adjustments for ImapMailReceiverTests
22acf51 Increase timeout in the ImapMailReceiverTests
4fdbdf1 GH-8577: Revise ImapIdleChannelAdapter logic (#8588)
22d47e7 Use Java text blocks for scripts in code
775e6fd (GH-8581) GH-8581: Don't overwrite external SshClient