Build Scripts should check command exit code in addition to invocation success

[vringar]

Describe the bug

As far as I could tell from a quick search most Command invocations in build.rs files only use a single unwrap on the result of the status(). However, the first unwrap only covers a failure to invoke the command, not whether it completed successfully.
Mara Bos has confirmed this in this comment.

To Reproduce
Steps to reproduce the behavior:

1. Don't install a required dependency to build qemu
2. Run cargo build --no-default-features -p libafl_qemu
3. Observe that the first error reported by the build script is Failed to read linkinfo.json as that is the "observable" error condition from the perspective of the build script.

Expected behavior

I would expect the error to be accurately attributed to the failing command.

Additional context

There are a couple of different ways this is handled in other buildscripts

LibAFL/libafl_libfuzzer/build.rs

Lines 79 to 82 in 374f873

	assert!(
	command.status().map_or(false, |s| s.success()),
	"Couldn't build runtime crate! Did you remember to use nightly? (`rustup default nightly` to install)"
	);

LibAFL/libafl_nyx/build.rs

Lines 10 to 14 in 374f873

	if status.success() {
	println!("success to run ./build_nyx_support.sh");
	} else {
	panic!("fail to run ./build_nyx_support.sh");
	}

But there are also a lot of unhandled cases elsewhere like

LibAFL/fuzzers/backtrace_baby_fuzzers/forkserver_executor/build.rs

Lines 26 to 30 in 374f873

	Command::new("git")
	.arg("clone")
	.arg(AFL_URL)
	.status()
	.unwrap();

LibAFL/libafl_frida/build.rs

Lines 31 to 33 in 374f873

	.status()
	.expect("Failed to build test harness");
	}