Clean up log4j-spring-cloud-config-client dependencies

[ppkarwasz]

We minimize the dependencies of log4j-spring-cloud-config-client to those really required: spring-context and spring-cloud-context.

The dependency on spring-boot-autoconfigure is optional (its just used in annotations) and the artifact can be also used without Spring Boot.

Fixes #2157.

[raffig]

It seems to be OK, however from my personal point of view I would say that Spring related properties should not be in log4j-parent/pom.xml, because in general log4j has nothing to do with Spring. Only this module depends on Spring, so I would place it in log4j-spring-cloud-config-client/pom.xml. What you think?

[vy]

I recently put significant effort to get log4j-parent rid off Spring-related dependencies. @raffig agrees with the earlier design too, see his comment. Could you please update the PR such that log4j-parent is untouched and log4j-spring-cloud-config-client changes only contain the fix to #2157, please?

[ppkarwasz]

@vy,

I moved the Spring dependencies back to log4j-parent, because I managed to remove spring-boot-dependencies and spring-cloud-dependencies from the imported BOMs.

Since these dependency-management-polluting artifacts are out of the picture, I don't see a difference between log4j-spring-cloud-config-client and e.g. log4j-mongodb4: the dependencies of the latter are also in log4j-parent, even if no other artifact uses them.

[raffig]

I would say that dependencies specific to log4j-mongodb4 should be in that module as well.

[ppkarwasz]

To be clear, the parent module log4j-parent does not depend on any of these libraries, it only contains them in the dependency management section.

@vy, why should spring-cloud-context versions be managed in the log4j-spring-cloud-config-client, when at the same time all the other dependencies are managed in the parent module?

[vy]

@ppkarwasz thank you so much for your effort and understanding in this PR. You also have done a great job by introducing our agreement here as a general policy to the Log4j team. All in all, thank you very much! 🙇