casey
Add windows-script-interpreter setting
Discussed here: https://github.com/casey/just/issues/2260#issuecomment-2741516734
I did my best to copy coding conventions from windows-shell, but I'm not a rust expert.
Worth noting that, although this does solve my use-case -- pointing to a different sh on Windows than Linux -- it doesn't let you [script('linux-shell')] and [windows-script('windows-shell')]. If you're specifying shell inline within the attribute, you can't specify a different option for Windows and Linux. For that, you're still better off using #!{{SHEBANG}} and setting that variable conditionally.
Tests are failing locally for me, but I suspect that's because my bash.exe is WSL2, but tests try to use it as a Windows bash shell. I'm opening this PR to get some initial feedback; don't want to waste time fixing my local testing issue if this PR can't be merged for other reasons.
