Upgrade to Log4j2 2.25.1.

Comment From: snicoll

So the upgrade requires a bit of work (WIP):

  • @PluginLoggerContext now requires a public setter even if the class is not.
  • GraalVmProcessor now requires log4j.graalvm.groupId and log4j.graalvm.artifactId properties. This kicks off for any use of those plugin annotations.
  • https://github.com/spring-projects/spring-boot/issues/46035

Comment From: wilkinsona

Re-opening due to https://github.com/apache/logging-log4j2/issues/3893.