Remove remaining mentions to subsystem=security in Elytron guide

There are some remaining mentions to /subsystem=security in the documentation that should be removed.

See eg. /subsystem=security:write-attribute(name=initialize-jacc, value=false) in https://github.com/wildfly/wildfly/blob/main/docs/src/main/asciidoc/_elytron/Elytron_and_Jakarta_Authorization.adoc