Have you tried asking your university's IT department? It's possible they might unblock the website if you ask. They may be using a pre-built filter, with a blacklist of "gaming" websites and can whitelist
lichess.org. The worst that would happen if you ask is that they say no, ignore your request and say nothing, or laugh privately among themselves at the "loser chess nerd," none of which is a big deal. But I think you have a nonzero chance of getting Lichess unblocked because of the perceived educational value of chess.
If you want to make a stronger case to unblock Lichess, you could get your university's chess club to make the request, and if your university doesn't have a chess club, consider starting one yourself.