That's supposed to be a real good guitar. If it's new Gibson needs to see that. If it's still owned by the store then I'd let them keep it/deal with it. If you own it and it's under warranty have Gibson or the store fix it.
Looks like the crack is in the finish between the nut, fretboard, and neck. I've had something similar happen to my unbound LP Junior in the same spot. Probably has something to do with the way all three of those parts interact with temp. and humidity. My Junior's a case queen. It started showing up several years after buying it.
I am not a repairman. Back in 1966, I bought a brand new Gibson SG. Shortly after and during a practice session, I turned around suddenly and my neck hit the bass player's neck. It was a pretty violent hit. I didn't notice right away but my neck had a bad crack. The crack extended almost from one side to the other. I was only 15 at the time and was devastated. So I bent the neck a bit so that the crack would open and applied LePage's wood glue. I don't think that I even had a clamp but I managed to set it so that pressure was applied to that crack so that it would be as tight as possible. I played that axe for 19 years steady until I bought other guitars. I still have it now and it still plays great.
Mahogany or not (not sure what mahogany has to do with it) but I'd walk away. No sense in buying something that's already damaged just to save a few bucks only to always be worrying about it or having to deal with it when it becomes worse.
It's always worth biting the bullet and sucking it up and spending a little more if that means getting the exact guitar you want. The money saved will be forgotten about pretty quick and you'll probably not be happy with it compared to just buying what you want. As the saying goes, "buy once, cry once".
I wouldn't consider it, especially as a new guitar. I'd pressure the big box store to send it back to Gibson and have Gibson send a carefully inspected new one to replace it without delay. Don't accept anything like due to the "delay in supply chain" you'll have to wait 9 months. Although there are serious delays Gibson can find one, inspect it and get it to you in a reasonable amount of time if the box store buyer puts some pressure on them. If they can't shop elsewhere.