Magnetic Dice Tray, No Drawer

Please see @platcham’s original [Magnetic Dice Box, Tray, and Tower](https://www.thingiverse.com/thing:2511974) for the rest of the parts of this thing.

This is a simple remix of the “Tray Top, No Designs” part to remove the holes that connect it to the dice drawer underneath, since I did not want to use the drawer. I also found that the vertical holes were so close to the outer corners of the tray, that it led to skips/breaks in the outer wall. Removing these holes also fixes this cosmetic p