https://javadoc.jenkins.io/hudson/tasks/LogRotator.html

Jenkins.instance.getAllItems(AbstractProject.class).each {it ->
    if (it.builders.size() == 0) {
        return
    }
 
    println '=============================================================================='
    println it.fullName
    if (it.logRotator) {
        println it.logRotator.numToKeep
        println it.logRotator.daysToKeep
    } else {
        println 'EMPTY LOG ROTATE!!'
    }
    println '=============================================================================='
    println ''
    println ''
}