I don't think there is one right thing to do. You do have the option of putting some clear on it. But I don't think that it will help. Particularly since it doesn't appear the gash goes down to the fabric. At least not in that picture.

I'd just ride the bike and every once in a while check it to see if any bad is happening. Though at that point, a new bike or costly repair will likely be in order. But clear epoxy or other might just cover up the future bad events so you aren't able to see them happening. Till they show you otherwise at least.