Run --version at the end

E.g. dtolnay/rust-toolchain has this as the last step
```
Run rustc +nightly --version --verbose
rustc 1.90.0-nightly (3048886e5 2025-07-30)
binary: rustc
commit-hash: 3048886e59c94470e726ecaaf2add7242510ac11
commit-date: 2025-07-30
host: x86_64-unknown-linux-gnu
release: 1.90.0-nightly
LLVM version: 20.1.8
```