unix: enable vectorio in coverage build

[jepler]

I noticed #9753 and thought: wouldn't it be nice if we could test it on host computers. It turned out to be relatively easy to add the vectorio module to unix coverage builds.

$ ./build-coverage/micropython 
CircuitPython 9.2.0-rc.0-1-g2f1102da6a-dirty on 2024-10-28; linux [GCC 12.2.0] version
Use Ctrl-D to exit, Ctrl-E for paste mode
>>> import displayio, vectorio
>>> palette = displayio.Palette(1)
>>> circle = vectorio.Circle(pixel_shader=palette, radius=25, x=70, y=40)
>>> circle.contains(0,0)
False
>>> circle.contains(74-24, 40)
True
>>> circle.contains(74-26, 40)
True

this would enable writing tests of vectorio features (other than rendering anyway) that can run during CI on a host computer.

[FoamyGuy]

Neat! Thanks for adding this.

I tested it successfully with a unix port build locally. (my first time building the unix port 🎉 )