python 3.12: utcnow function is deprecated
    
    The following warning is displayed on a system running with Python 3.12:
    -------------------
    /usr/lib/python3.12/site-packages/ipalib/rpc.py:925: DeprecationWarning:
    datetime.utcnow() is deprecated and scheduled for removal in a future
    version. Use timezone-aware objects to represent datetimes in UTC:
    datetime.now(datetime.UTC).
    
      timestamp=datetime.datetime.utcnow())
    -------------------
    
    Fixes: https://pagure.io/freeipa/issue/9425
    Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>