No, it's Programmable. Though it's not actually programmable. I should've written Custom Search Engine instead, that's also a name for it.
cse.google.com - It's quaint that past the modern landing page, when using the search portal today, you still get some outdated iteration of Google UI design.
It's used, for example, for making OSINT searches.[0] Or at some point by at least one Wikipedia editor for a custom list of Reliable Sources for Anime & Manga.[1]
You could run Sourcegraph and import/sync those repositories.
Or you could run your own ElasticSearch/Melisearch and crawl the websites yourself (if you're interested in things other than git repositories).