windows doesn't respect the shell
Describe the bug Unlike on macos where nushell works fine, windows is hardcoded to use cmd
To Reproduce
I discovered it here: https://github.com/jesseduffield/lazygit/issues/4047#issuecomment-2954067602
It wasn't obvious at first but after debugging it I realised it was using cmd /c despite $env.SHELL being set.
Then I tracked it back to https://github.com/jesseduffield/lazygit/pull/4385 and discovered the hardcoded case for windows.
Expected behavior To work as other os, I specifically use nushell because of how powerful it is at being cross platform.
Ultimately for me this whole shell thing shouldn't be hardcoded or only fallbacks and expose both as options
Version info: No sure why but building from master I only get:
commit=, build date=, build source=unknown, version=unversioned, os=windows, arch=amd64, git version=2.49.0.windows.1