Fix short linker error output

This PR does 2 things:

- It removes the braces when there's a single element. This is required since brace expansion (at
  least in bash and zsh) only triggers if there's at least 2 elements.

- It removes the extra `.rlib` suffixes of the elements. See
  https://github.com/rust-lang/rust/pull/135707#discussion_r2185212393 for context.

Running `cargo +stage1 build` on the following program:

```rust
unsafe extern "C" {
    fn foo() -> libc::c_int;
}

fn main() {
    let x = unsafe { foo() } as u32;
    // println!("{}", data_encoding::BASE64.encode(&x.to_le_bytes()));
}
```

Gives the following diff before and after the PR:

```diff
-/tmp/foo/target/debug/deps/{liblibc-faf416f178830595.rlib}.rlib
+/tmp/foo/target/debug/deps/liblibc-faf416f178830595.rlib
```

Running on the same program with the additional dependency, we get the following diff:

```diff
-/tmp/foo/target/debug/deps/{liblibc-faf416f178830595.rlib,libdata_encoding-84bb5aadfa9e8839.rlib}.rlib
+/tmp/foo/target/debug/deps/{liblibc-faf416f178830595,libdata_encoding-84bb5aadfa9e8839}.rlib
```

Do we want to add a UI test?

0 files changed, 0 insertions, 0 deletions