springboot Remove requirement for Spring MVC to be on the classpath for hypermedia-based autoconfig

Spring HATEOAS now supports both Spring MVC and Spring WebFlux.

Test cases that prove HypermediaAutoConfiguration properly backups off when Spring MVC is missing need to be dropped.

Comment From: gregturn

Depends on #20374, #20372, #20373.

Comment From: gregturn

Per our video chat, this requirement is null and void. When we have a better story regarding media type aliasing, we can revisit.

For related bits of hypermedia-based client configuration, see also https://github.com/spring-projects/spring-hateoas/issues/1223, https://github.com/spring-projects/spring-hateoas/issues/1224, and https://github.com/spring-projects/spring-hateoas/issues/1225