Panic parsing invalid UUID input "{}"

version = "1.23.2"

Using `Uuid::parse_str("{}");` causes 
```
thread 'main' (75) panicked at /playground/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/uuid-1.23.2/src/error.rs:75:21:
attempt to subtract with overflow
```
Reproducible:
https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=b73d1ba4712236f57ac98ffb9d1c940e