Fix spurious not wrapped in act warnings

The versions of `@testing-library/dom` in use by
`@testing-library/react` and `@testing-library/user-event` got out
of sync. They're going to move it to `peerDependencies` in the
future to avoid this, but for now, I had to explicitly upgrade the
version used by the latter to align it with the one in use by the
former. See
testing-library/react-testing-library#1296 (comment)