I went through this recently in my career. In my case, my family had booked a cruise and prepaid the airfare from USA to Spain, all before I even started interviewing for the new job. In my case, the trip was prepaid and nonrefundable, and would occur before my probation period ended, which would violate the rules of my probation.
When the hiring supervisor called me to offer me the position -- the informal offer before the formal, written offer came through -- I wasn't fully aware of the probation policy rules, but I told him about the trip and that it was nonrefundable.
He and I worked together to actually include the trip in the formal job offer, so it was in writing that they were making an exception to the rules.
I suggest a similar approach for you. Go through the interview process. If they make you an offer, let the hiring committee know that you've already booked a trip for dates X through Y, and you want to make sure that taking this trip will not cause any negative impact.
If the trip is after the end of your probation, then they shouldn't have a problem with it. And by letting them know up front, you're making it clear to the managers/hiring committee/etc. that you don't want to cause problems and want to be completely above-board about things.
The only reason I can see that this might be an issue is if you haven't saved up enough vacation time by the beginning of your trip. As long as your vacation accrual rates are good, you should be good, too. Otherwise, you may be forced to take the trip on leave without pay? But that's not really directly related to the original question. And by scheduling this at the beginning, you should have plenty of time to work through that.