Remove charset parameter from Spring MVC JSON content type

[sdeleuze]

With #22788, MediaType#APPLICATION_JSON_UTF8 is deprecated an WebFlux default content type for JSON is Content-Type: application/json but based on my tests with Spring MVC it is still Content-Type: application/json;charset=UTF-8. I suspect it is caused by

spring-framework/spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java

Line 255 in 73dbd06

((ServletServerHttpResponse)outputMessage).getServletResponse().setCharacterEncoding("UTF-8");

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