remove newsprint dots

Check your scanning software for a descreen filter. 3rd party scanning software like VueScan have it.

The technical term for what you want to do is "descreen" - since it is created with something called a "half-tone screen". Google that and you will get a number of techniques that any full photo editor - I use Photoshop Elements - can do. Though the tools in Photos probably can't.

Don't expect miracles, though.

Suggest:

https://docs.gimp.org/2.10/en/plug-in-despeckle.html