fix: handle broken pipe errors gracefully

[wfxr]

This commit fixed the panic when using ya with pipes:

$ ya pack --list | head -3
plugins:
thread 'main' panicked at std/src/io/stdio.rs:1123:9:
failed printing to stdout: Broken pipe (os error 32)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
zsh: IOT instruction (core dumped)  ya pack --list |
zsh: done                           head -1

When a broken pipe error occurs, we can exit gracefully with a success exit code. This matches existing Unix convention.