v6.1.5

Change log:

ed1bfc6 Upgrade to Spring GraphQL 1.2.4
c4e30a0 Revert to SSHD 2.9.2
5cb99d3 Fix Spring Data version
fb913e1 Upgrade dependencies; prepare for release
5d93c6a GH-8792: Fix File StreamingMS for one file filter
ef2575a Increase Timeouts in FTP RotatingServersTests
9227acd GH-8786: Make FtpSession.finalizeRaw() robust
59df2b9 GH-8785: Propagate WebSocket client connect fail
72ce758 Fix KV store for group-to-message relationship
cf5427f GH-8773: Fix MGS for removal from group
8cdead4 GH-8778: Fix KafkaMessageSource deadlock (#8780)
6ec2b88 GH-8779: MongoDbMS Fix distinct result conversion (#8781)
991d29e KafkaMessageSource: Lock instead of synchronized
91e806a GH-8770: Add PostgresSubsChannel.errorHandler (#8777)
4907316 Fix PostgresSubscribableChannel race condition