OK, so that just triggered a memory. I ran into this when I first transferred over to Ventura (13.2) in early Feb. Somehow I discovered that you needed to set up a "smart" album to hold the images for a screensaver. I did that, and it worked (last time). I checked Photos, and that smart album was no longer in existence. I set up another one and called in ScreenSaver and went back into System Preferences. Now "Photo Library ..." shows up in the selection of sources. I selected that, and up popped the attached image. The only one of these selections that worked was the one called "Screensave Selection" (which is NOT what I called that smart album).
So, since my Photos library did not have any of the albums shown in this list, just for fun I went back into Photos and delected the ScreenSaver smart albumn. The screen saver was still able to find the photos from this "Screensave Selection" choice. OK, so I closed everything down and rebooted. Still works with no smart album.
I have no idea what is going on here, but there is some undocumented (and buggy) interaction between Photos and the Ventura screen saver.