fix: update trait and remove unused io imports

Co-authored-by: aider (openai/andrew/openrouter/qwen/qwen3-coder) <aider@aider.chat>

src/meta_plugin/program.rs

@@ -1,6 +1,5 @@
 use anyhow::{Context, Result, anyhow};
 use log::*;
-use std::io;
 use std::io::Write;
 use std::process::{Command, Stdio, Child};
 use which::which;