Previously, when lazy initialization was enabled, STOMP-based WebSocket
messaging would not work as the stompWebSocketHandlerMapping bean was
not initialized and CONNECT requests would go unanswered.

This commit adds a LazyInitializationExcludeFilter that causes the
stompWebSocketHandlerMapping bean to always be initialized eagerly.
This triggers initialization of the WebSocket transport allowing
requests to be received and processed.

Fixes gh-19611