Closes gh-23984 *3a0f309e2c/spring-web/src/main/java/org/springframework/http/codec/ServerSentEvent.java (L24)*3a0f309e2c/spring-web/src/main/java/org/springframework/http/codec/ClientCodecConfigurer.java (L88)*ef14d76d36/spring-web/src/main/java/org/springframework/http/codec/ServerCodecConfigurer.java (L94)*3a0f309e2c/spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/handler/EventSourceTransportHandler.java (L33)