Since you have mentioned that you have already deleted this listing from your inventory, please understand that listings are not removed from the Account Health page even if you change the listing's status (e.g. closing or deleting the listing from your inventory). The violation will continue to display on your Account Health for a period of 180 days.

However, this will not affect your performance metrics anymore since you have already deleted the listing.

Rest assured that the violation will be removed in your account after 180 days have passed.

For more information about Account Health, please see the link below:
https://sellercentral.amazon.com/help/hub/reference/GQLQRT6FX2K7C8Y5