SpringBoot Fix Mockito package-info.java deprecation warning

> Task :spring-boot-project:spring-boot-test:javadoc
/Users/pwebb/projects/spring-boot/code/3.4.x/spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/package-info.java:19: warning: Tag @deprecated cannot be used in package documentation.  It can only be used in the following types of documentation: module, class/interface, constructor, field, method.
 * @deprecated since 3.4.0 for removal in 3.6.0 in favor of Spring Framework's
   ^
1 warning