Added a test to verify that layout.removeRegion removes the region from ...

### Why
Upon researching the layout.removeRegion function to see if it removes from layout.regions, I noticed that it does in the dev branch, but there wasn't a test for it.

### What
This PR is 1 expect added to the layout.dynamicRegions test specs

### How
It adds the missing test

### Discussion
I don't see how this would cause any problems with anything else.