s4:rpc_server: make use of dcesrv_assoc_group_common_destructor()

s4:rpc_server: make use of dcesrv_assoc_group_common_destructor()

Currently this should not be needed, but it's better to
call dcesrv_assoc_group_common_destructor() in all assoc_group
destructors.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15765

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
(cherry picked from commit 19657be71d7cec5ac58a5d6969dc1d6ae7c5b517)

Autobuild-User(v4-20-test): Jule Anger <janger@samba.org>
Autobuild-Date(v4-20-test): Wed Dec 18 09:51:41 UTC 2024 on atb-devel-224