It is against the rules? I thought it's all fair game, but you are time constrained
If anything, I'd think allowing looking stuff up would benefit human players over ChatGPT (though humans are probably much slower at it, so they probably lose on time).
It's important to have fair and equivalent testing not because that allows people to win, but because it shows where the strengths and weaknesses of people and current AI actually are in a useful way.
Alternative example: "I wondered what the rules actually say about web search and it is indeed not allowed: (link)"