New review comment by desertsagebrush on void-packages repository

https://github.com/void-linux/void-packages/pull/47870#discussion_r1436159058

Comment:
Specifically, I've updated it to have this for a post_build (with just this and the addition of the build-helper, it is now failing on all builds...hence why I'm not pushing it):
```
post_build() {
	cargo auditable build --release --package xtask
	vtargetrun  "CARGO_MANIFEST_DIR=./xtask target/x86_64-unknown-linux-gnu/release/xtask generate-manpage"
}
```

Right now the rust target triple for the host architecture is hard-coded, as there doesn't seem to be a generic `xbps-src` variable for that since `XBPS_RUST_TARGET` is for the target. Definitely not quite ready to be merged yet.