Friends birthday when I don’t drink.

Hi this is such a stupid question but I just need some help.

I’ve been friends with these group of girls since school. I don’t feel close to them anymore tbh & don’t find I have much in common with them. We still meet and I go just for the sake of it. The big thing is every meet up involves drinking, which I don’t do anymore. Back years ago, I was a drinker. Maybe that’s all we had in common? Anyways, I tend to go, drive and not drink and it’s all fine. But one of the girls birthdays is coming up, she’s doing bottomless brunch. I really do not want to go. I think they can obviously tell I don’t drink when we meet but I don’t think they know that I’ve stopped drinking completely. And for some reason, I don’t seem to have the courage to say. Its so stupid, like im worried im going to get judged but I suppose it’s just me feeling left out. Do I just make an excuse completely, or go & say I don’t want to drink?