Make the repository less unix-centric

[jprochazk]

A lot of tooling in this repository assumes that:

• bash exists (and that the user's shell understands hashbangs)
• symlinks just work ™️

I think removing these two assumptions will make the repository much more accessible to Windows users.

• scripts/setup* don't work on Windows, meaning they can't easily install required tooling
• re_web_viewer_server is configured to fetch the web_viewer files via a symlink which doesn't work when the repository is freshly cloned
• a lot of just recipes use bash (such as py-build, which is central to everything regarding the rerun wheel)

More investigation needs to be done to find all the other things which don't work on Windows out of the box.

[emilk]

The instructions for Windows were improved in #2319

[jprochazk]

@Wumpf what's your experience like now? Are there any remaining snags?

I've had great success using pixi on Windows/Mac for everything. It Just Works™️, and I haven't had to manually run the contents of any bash script yet. Unless you object, I would be fine with closing this now (especially since further progress for pixi is tracked elsewhere)

[Wumpf]

Yeah let's close this. There's still some details that don't work like for example roundtrip test scripts aren't function yet on Windows and various scripts under /scripts/ don't work yet. just works by now but isn't great (looking forward to remove it completely)
The symlink in re_web_viewer isn't reaaaally a problem if git is configured correctly on windows. There's a note on BUILD.md by now