Use Python for scripting and get this working on Windows

[Prince213]

Currently I see no POSIX-specific utlities need to bootstrap Zig besides bash. Maybe we can switch to use Python for scripting to reduce dependencies. Another benifit for this is to be able to run this on Windows.

[Prince213]

By using Python, we can also do patching in Python scripts, which could be a solution for #61 .

[daurnimator]

Python is far more of a dependency than a shell. The scripts intentionally work with any POSIX compliant shell; not just bash.

[Prince213]

It's attractive to run this on Windows, and it does no harm (we need Python anyway).

[nektro]

it'd be better to add a powershell/batch script for windows because otherwise the python script would need to special case windows regardless

[LinuxUserGD]

it'd be better to add a powershell/batch script for windows because otherwise the python script would need to special case windows regardless

See https://github.com/ziglang/zig-bootstrap/pull/140