switch to uvu

[atk]

Uvu does not require babel, it can run the tests comfortably without it.

I'm not sure if this works together with the internal test runner and I am not sure if this will work at all.

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

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[keiravillekode]

Have you looked at https://github.com/exercism/wasm-test-runner/ ?

Ideally we should add to the wasm repo a script like https://github.com/exercism/generic-track/blob/main/bin/verify-exercises-in-docker

[atk]

This does not work, since the global tests are still run with jest. Too bad.