Experiment with SWC instead of Babel for Jest tests

https://twitter.com/JoshuaKGoldberg/status/1495890562704191489

As poked by @bradzacher: I [saw very nice test performance improvements](https://blog.joshuakgoldberg.com/jest-babel-to-swc) in tslint-to-eslint-config. It'd be nice to try that out here.