With a local build of WildFly main branch, I can run `./standalone.sh -secmgr` with Java 21 but not `./appclient.sh -secmgr` which fails with:

Exception in thread "main" java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release
at java.base/java.lang.System.setSecurityManager(System.java:429)
at org.jboss.modules.Main.main(Main.java:418)