SketchUp 2024 release and designPH v2.1.15 compatibility

SketchUp 2024 is now released. In our testing with designPH v2.1.15a we found that the change to Ruby 3 has caused a number of issues which make designPH v2.1 incompatible with SketchUp 2024.

Most of these issues have already been solved during the development of designPH v2.2 which is in the final stages of preparation.

Note that if you are a new SketchUp customer, you can still download SketchUp 2023 from https://www.sketchup.com/download/all