I accidently hit approve instead of reject on a suggested edit on Academia SE. Is there anything I can/should do about it like an undo or something like this?
Is there anything I can/should do about it like an undo or something like this?
No, there isn’t (probably it would be needed only very rarely). All you can do is wait for the edit to finally fail or pass review and act upon it in the latter case. If I am identifying your case correctly, the former should just have happened.
Do not worry too much. Nobody is going to bite your head off for one wrong review.