3D `scalarplot` of constant functions crashes

```
using GridVisualize, GLMakie, ExtendableGrids
scalarplot( grid_unitcube(Tetrahedron3D), (x) -> 42,  Plotter = GLMakie)
```

crashes with 
`ERROR: Invalid text boundingbox GeometryBasics.HyperRectangle{3, Float64}([109.0, NaN, 0.0], [41.97999811172485, 11.649999618530273, 0.0])
`

same also for `PyPlot`.