v5.4.12

Change log:

390400b Fix ExpressionUtilsTests for SF compatibility
7c72fdd Upgrade dependencies; prepare for release
43b78e0 GH-3675: Restore nativeHeaders for WebSocketInChA
83a488c Fix WebFluxMH for proper response handling
81a50ff GH-3652: File gateway: don't try delete no file
3f4368c GH-3648: Fix @Gateway.payloadExpression
5e6e638 GH-3641: Handle duplicate cookies properly
8a5c037 GH-3637: Fix KafkaMessageSource First Poll