`-Z build-std=std` pulls in `test` crate and fails

This started happening on this nightly:

```
$ cargo +nightly --version
cargo 1.71.0-nightly (ac8401032 2023-05-02)
```

This can be reprod in an empty crate:

```
$ cargo init repro
$ cd repro
$ cargo +nightly build -Z build-std=std --target wasm32-unknown-unknown
error: Package `test v0.0.0 (.../lib/rustlib/src/rust/library/test)` does not have the feature `backtrace`
```
