Imo this problem would be fine in either Go or Rust. I've done both. For extreme cases you can, i imagine, make Rust parallelism faster than Gos, but by default if you just design them similarly -- eg: throwing Tokio at the problem and not hyper optimizing Rust -- i imagine they'd perform quite similarly.
As much as i'm a proponent of Rust, Go is very capable and is generally a great language. Its warts (as i see them) are not going to be apparent in the parallelism needed for a Git hook manager lol.