Do I have to commit to the school that accepted me on the wait-list?

I have accepted my wait-list offer from UCSB, however I have also been accepted to Georgia Tech (committing).
I do not want to attend UCSB anymore.
However, if I was accepted off the wait-list from UCSB, would it mean I am forced to attend UCSB?
I would very much like to withdraw my application, but I somehow can’t find the option on the admission portal.

No - if you are accepted off a wait list, you are given a short amount of time to accept or decline the offer. Accepting a place on a wait list is not binding.

That said, please call or email them and have your name removed, giving another student a chance.