Same issue here. Just upgraded to 13.1 from 12.6.1 and my screen is flooded with these messages every few minutes. It seems to be connected to compiling / installing software (e.g. from macPorts). It's really annoying and it always lists the same items over and over. What's more: it does not provide a way to remove these items. I've disabled the respective ones already, but this does not change anything about the notifications.

Also see https://piunikaweb.com/2022/12/09/macos-13-ventura-background-items-added-notification-issue/