This is plain rude and unprofessional.
Yes, I would inform the boss about this one. You are leaving soon, true, but this sort of behaviour is unacceptable. It needs to be addressed, and even if they don't do much about it, it will be on record. That way if it happens again with someone else (or you, in your remaining weeks), it will be noted that it's not a one-off but a more concerning pattern of behaviour.