Clean up previous version install locations and check if other locations are still installed

### Most appropriate sub-area of Processing 4?

PDE

### Processing version

4.4.3

### Operating system

all

### Steps to reproduce this

#1022 left some todo's that did not block the PR but should be cleaned up at some point. 

### snippet

_No response_

### Additional context

_No response_

### Would you like to work on the issue?

I can, but happy for someone else to dive into