Polish configuration property reference

[mhalbritter]

@sbrannen found a bug in our documentation: There's a configprop:spring.aop.proxy-target-class in https://docs.spring.io/spring-boot/reference/features/aop.html.

That should be configprop:spring.aop.proxy-target-class[].

[wilkinsona]

There's one in https://docs.spring.io/spring-boot/docs/3.2.x/reference/html/web.html#web.servlet.spring-mvc.content-negotiation too. It references spring.mvc.throw-exception-if-no-handler-found which is deprecated. I've opened #42164 for that.