Migration to Spring Boot 4 section aop-starter-pom is misleading

[michaldo]

https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-4.0-Migration-Guide#aop-starter-pom

AOP Starter POM
(...)

If your application does not use AspectJ, typically an annotation in the org.aspectj.lang.annotation package, you probably do not need the starter at all.

I do not have org.aspectj.lang.annotation, I removed the starter at all and annotation io.micrometer.core.annotation.Timed stopped working.

I made PR for that in #48258

I think migration guide too carelessly suggests removal of spring-boot-starter-aop/spring-boot-starter-aspectj

[philwebb]

Thanks for the PR, but the situation is a little more nuanced than suggested. I think we'll update the wiki instead to help indicate that AspectJ might still be useful when combined with Micrometer.

[philwebb]

See #48258 (comment) which is a fair point. We should probably add something to the docs as well.

[snicoll]

I've added more details in that section.