I had the exact same problem, but it was solved when I installed the correct SDK version.

Since the PySpin module is looking for "libSpinnaker.so.4" and you are using Python3.10, it seems you that you have installed the python wheel for Spinnaker 4.x.x on Ubuntu 20.04. However, you should install Spinnaker 3.2.0.62 and use Python3.8 if you are on Ubuntu 20.04.