Will be handy to use it in our other scripts in the future too - thanks
Rumo!
Results of benchmarking ./run before and after these crate splits:
- Touching a proto file leads to a slight increase: about +90ms
- Touching an rslib file leads to a bigger decrease, as there's less to
recompile: about -700ms
And ./ninja test is even better: about +200ms and -3800ms.
