Do I really have to answer the phone if I end my friendship?
Why won't you respond if he calls you?
I don't care about him anymore.
Even if you don't care about someone the way you used to, ghosting their phone calls is not the way to handle things. Be honest with your friend and end the relationship instead.
I'm going to end this here.
It is still rude. You both need closure for your friendship. Can you imagine how much shock you would be in if a friend you did like ghosted you?