This sounds like an awesome pattern, and I had no idea it exists!
Simon Willison calls it the “baked data pattern” — where a read-only copy of your data is checked into your repo alongside your code. [1]
(And, just to tie the threads together, that’s the same Simon who wrote the OP we’re all commenting on, and who is also the co-creator of Django and more recently of the very handy Datasette!)