ptx <<< "🎉 34054698701234657890123456789 0" panics

https://github.com/uutils/coreutils/pull/10836 but
```
$ ptx <<< "🎉 34054698701234657890123456789 0"

thread 'main' (7390) panicked at src/uu/ptx/src/ptx.rs:492:5:
assertion failed: max_before_size >= before.len()
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```