Cetus Y axis endstop holder

If you are updating Cetus mk2 CPU to TinyFab CPU, you need to [get the end stops](https://www.tinyfab.xyz/product-page/cetus-mk2-to-mk1-downgrade-end-stops-pack-of-3), and add them to your printer.The end stop holder provided by Tinyfab conflicts with the default mk2 Y cable holder. I merged both into a single part, and made it look minimal. It also has slots for the end stop wire, which you can then route inside the Y cable so it looks nicer. (i.e. cut open the heat shrink at both ends, run the end stop wire through the nylon sheath and add the heat shrink back.)