You could cut a slot in the 35mm can and run the film around the outside. I have a 120 format panoramic camera that runs film around 120 degrees without rollers - just guides.

But a 35mm format pinhole camera with a focal distance of under 25mm is going to need a very fine pinhole to be worth doing. And if you put the pinhole on the circumference of the cylinder the distance to the curved film plane will vary. To use a curved film plane you normally use a half cylinder and put the pinhole in the middle of the flat face to get a constant distance along one axis of the image. You still get light fall-off.