block_retired.py: Do not login to the koji session
    
    The koji calls to list the packages in a tag are unauthenticated
    so there is no need to login. The login call has been failing due
    the session options not being passed to the session. However to
    complete the intended function we do not need to login, so lets
    not.
    
    Signed-off-by: Dennis Gilmore <dennis@ausil.us>