Explain why the Java version was capped at 24 for Kotlin modules

Adds an explanatory comment to Maven pom.xml files in modules that were held at Java 24 because they compile Kotlin and depend on kotlin-stdlib older than 2.3, which cannot target Java 25 bytecode. The comment names the kotlin-stdlib version found and the next step needed to reach Java 25. Self-healing: the comment is added while the module is at Java 24 and removed again once the module reaches a higher Java version (for instance after its Kotlin was upgraded to 2.3), so it only ever remains on modules that truly stay at Java 24 — whether a Kotlin 1.x cap or a 2.0-2.2 module whose Kotlin upgrade could not be applied. Intended to run last, scoped to modules that compile Kotlin.