I was able to accomplish this by doing each test within its own transaction session that gets rolled-back after each test. This way I'm allowed to modify the database to suit my needs for each test, then it gets magically reset back to its known state for the next test. Transaction rollbacks are very quick.
Unfortunately a lot of our tests use transactions themselves because we lock the user row when we do anything to ensure consistency, and I'm pretty sure nested transactions are still not a thing.
Migrations are kind of a different beast. In that case I just stand up a test environment in Docker that does what it needs, then just trash it once things have been tested/verified.
