Exactly my observation as well. They devour absolutely everything, no exceptions. No matter how stupid it might be to digest a source code repository via HTTP. They probably don't even recognize what's inside those pages and that there's an easier way to obtain the same result.
But gitweb is probably the second most used method of hosting a git repo and easily recognizable through heuristics. If it’s gitweb, fallback to git access and save everyone, including the crawler, time and resources.
No, when I said this behaviour is stupid I did not imply that it needs to be solved with "intelligence". This class if problem is already solved by traditional crawlers, AI companies just actively chose to disregard any of that in their race to the top / bottom.