I dislike AI but I think it's unfair that you're being downvoted for this.
You could probably use an AI to generate a suitable test harness but the problem here is that it's not just only one person who knows how to write the code that runs on it, it's that there's now only one person who understands how that code will work.
You're familiar with what bugs are, right?
I'm going to send you down a bit of a rabbit hole here - https://www.bigmessowires.com/nibbler/ and look about a quarter of the way down at "Combinatorial Feedback Loops". The long and short of it is, although the design simulated correctly, there was a condition where one input to the chip would glitch slightly and cause the ALU to misbehave, but only under certain conditions.
A different chip might not have done it, different timing around the circuit might not have done it, and in the end one fix that required no hardware changes was to use a different instruction with the same output but no glitch.
I'm prepared to bet that Voyager's computers are absolutely chock full of nonsense like that, and there's a lot of "correct per the spec" code you could write that could send it off into la-la land because it doesn't quite work right on the real hardware.
And that specifically is where you need a human to say "yeah but it needs to be written with *these* specific opcodes because *those* specific opcodes will...", and I'm not sure that AI is ready to do that yet.
The root of the problem is the one I run into if I wanted to use AI to write code - AI is a big copy-and-paste machine and does not really understand all the tiny details that we hold in our brains.
Without the implicit knowledge that goes around things like "well you can't do that because..." you're going to get into a mess.