True, but I'm also pretty sure it was described as infinite in the classic series, too.
I just searched Chakoteya's Doctor Who
transcript site for the word "infinite" (by googling "infinite site:http://www.chakoteya.net/DoctorWho/"), and didn't find any such instances. No luck with "endless" or "limitless" either.
Anyway, people often use "infinite" figuratively to refer to things that are mathematically finite but vast enough to be effectively limitless from the observer's point of view. Actual infinity is a rather untenable concept when it comes to physical reality anyway. It's easy to say the word, but harder to grasp its true meaning or ramifications. So it's always best to be skeptical when you hear anyone using the word.