You apparently don't have a flat.
I'd carefully probe to make sure you don't have any glass stuck in there, but it looks clean.
I assume it is still blown up, full pressure, so no tube is sticking out.

Personally I'd go ahead and ride it as is on the rear.

You might consider a boot the next time you get the tire off.

Park makes boots for not too much. They are meant to be temporary... but... perhaps good for longer. They're pretty big. When I got a hole like that in my Schwalbe Marathon (deep enough to puncture the tube), I rode it for a few days without a boot, then put a Park boot in. It was too big and caused the tire to bump, so I cut it in half, rounded the corners and put it back in. So far I got 500 or so miles on it without further issues. It is strong, but seems to be too rigid with pretty abrupt edges, however so far it is ok (always have a spare tube with me).

You could also try something like shoe goo, or perhaps a radial tire patch on the inside.

Anyway, it is up to you. As long as the casing is mostly intact, you're probably ok, but you can try something to give you some peace of mind, as well as protecting from debris striking the same spot.