The issue is actually caused by the beige 0.6 pt border that sits around the main graphics. It is currently set as a dashed line (which I don't think is intentional) and for some weird reason this is causing AD to hang when exporting the file to PDF resulting in the file either not being written at all or taking an absolute age to write so this looks like a potential Bug.
If you simply change it from a dashed line to a solid line the problem goes away and the file exports as expected.
It actually has nothing to do with the images in your file, though I noticed your images use a mixture of different ICC profiles and resolutions resulting in some uneccessarily large file sizes and some files with a placed dpi that falls below 300. The majority of images are sRGB but one is Display P3 and another has no ICC profile at all.
Depending on the intended final output for the file, it may be a better option to size your images prior to placing them in AD so you end up with something more like this, all using the same ICC profile, but that all depends on how the file is going to be used?
any news on the release of the official AP version that will fix the saving back into Mac OS Photos problem that has been known for EIGHT MONTHS now??...
