SpringBoot Remove mentions of JUnit 4 from javadoc and reference documentation

Spring Framework 7 has deprecated support for JUnit 4 and will remove it in 7.1 or 7.2. Aligned with this, we should consider what we want to do and when. For example, our javadoc mentions JUnit 4 in a number of places such as:

https://github.com/spring-projects/spring-boot/blob/96afc3f944f0dd25d54f0a339ee2a5760ccfddf0/module/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/orm/jpa/DataJpaTest.java#L66-L67

This is common across many (all?) of our test slice annotations. Should we remove this and similar now or wait until support's completely removed from Framework?