Update pprof-rs to enable `framehop`-based unwinding

Newer versions of pprof-rs support the `framehop` crate for unwinding which is potentially better in cases where `backtrace-rs` causes panics and frame pointers lack information. Also would require a new feature in the `pyroscope_pprofrs` crate to enable `pprof-rs/framehop-unwinder`.

Thanks