That's borderline between tread and sidewall, so does make decision a little tricky. Does it even leak? If no, pull it and monitor. Tire shop probably want to sell you a new tire, but they might patch it, or you could fix it yourself:
Same here. I plugged a tire myself once on another car in that same area. No one wanted to patch/plug it so I just used one of those DIY kits to plug it from outside.
It lasted until I had to throw the tire, maybe around 40K miles.
What you can do is plug the tire with a DIY kit, mark it with white paint and drive around. Avoid highways and high speeds. check every 5 miles in the beginning. If ever you see the the plug moving, ditch the tire.
That's what I would do for my own tire. Try at your own risk.