Support _netrc files for windows

[jurkov]

Uv does need a .netrc file on Windows. Unfortunately, pip needs a _netfile on Windows.
Uv should also use a _netfile on Windows.

This Issue is similar to #1405, but it's different.

Source: https://stackoverflow.com/questions/6031214/git-how-to-use-netrc-file-on-windows-to-save-user-and-password

[zanieb]

Can you share some more about this? We're just using the rust-netrc crate which should look in your home directory as described?

https://docs.rs/rust-netrc/latest/src/netrc/lib.rs.html#60-71

[zanieb]

Ah the title vs the issue confused me, you're saying we need to support _netfile? You can use the NETRC variable to point to an arbitrary file path.

[jurkov]

Well, I created an issue at gribouille/netrc#1 as well.