Do not bundle Python 3 on Linux

[yanmaani]

Is your feature request related to a problem? Please describe.

Most Linux systems already include Python; if they don't, that arguably lies on the package manager, and it should be easy to install it. Bundling Python makes the download bigger and doesn't serve much of a point.

Describe the solution you'd like

Stop bundling Python on Linux. (Keep it on Windows.)

Describe alternatives you've considered

It would also be possible to keep doing it; this would especially be useful if their distro doesn't ship a recent Python. But in that case, shouldn't it at least be statically linked?

Additional context This is slightly more annoying because of #146.