Replace hard-coded interpreter with sys.executable
    
    Instead of hard-coding python3, the smart card advise script now uses
    the current executable path from sys.executable as interpreter.
    
    Fixes: https://pagure.io/freeipa/issue/7741
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>