Crate vendoring hangs indefinitely upon proxy issues

Hi!

We (Stripe) noticed that when vendoring crates `cargo-bazel` will hang forever in:

https://github.com/bazelbuild/rules_rust/blob/608af09e31a337132e6f80a8286aa9d3fd32ddc3/crate_universe/src/metadata.rs#L224-L239

due to the cargo commands not being configured with timeouts. Low-hanging fruit here would be setting some default timeouts here that make sense ☺️

Thanks for an awesome ruleset!

// F