Remove hardcoded directory for some footprints

[jradtilbrook]

Hey I've been playing around with modifying your corne v4 and run into some missing file issues. It seems to be that some of the parts here are using a dynamic path variable (and those work). But some paths are hardcoded to your local machine. See below:

This part works:

kbd/kicad-footprints/kbd.pretty/LED_WS2812B-PLCC4.kicad_mod

Line 28 in 930e7d9

(model ${KIPRJMOD}/kbd/kicad-packages3D/kbd.3dshapes/WS2812B.step

But this doesn't:

kbd/kicad-footprints/kbd.pretty/keyswitch_cherrymx_hotswap_1u.kicad_mod

Line 87 in 930e7d9

(model "/Users/foostan/go/src/github.com/foostan/kbd/kicad-packages3D/kbd.3dshapes/kailh_hotswap_socket.step"

See how the broken one has your local path hardcoded?

Even still, many of the footprints still use a different dynamic variable. So I'm not sure if this is the correct fix or whether other parts need changing as well.

[jradtilbrook]

I noticed the actions were outdated and had failed to setup python on the last run so I've updated those in an attempt to fix it as well.

[foostan]

Thank you for your contributions!

It's tricky for this kind of locally run software to get information about the local environment unintentionally, which was a path. I feel it is an issue.

CI is broken, but I'll merge it.