Finally block silents errors causing false-positive 0 exit code

Nobody has claimed this yet.

[the finally block in runner function](https://github.com/lukeed/uvu/blob/0f9dfb7df31d55d063ef7a1e943499f9f89ef97a/src/index.js#L83) silents every error which is thrown outside the inner `try` block.

Example:
```
import { test } from 'uvu'
test.before(() => {
throw Error()
})
test('foo', () => {

})
test.run()
```
although the console output correctly shows that 0 tests passed, the process exits with false-positive exit code 0 and prints no error

besides hooks, also internal errors may cause this, e.g. a [function for error formatting](https://github.com/lukeed/uvu/blob/0f9dfb7df31d55d063ef7a1e943499f9f89ef97a/src/index.js#L48) fails, when a string is passed as an error (`throw 'error string'`)

Start in src/index.js at the runner's finally block around line 83, then inspect the error-formatting function around line 48. Reproduce the failing hook and string-thrown-error examples; done means these errors are reported and the process exits with a nonzero code instead of a false-positive 0.

Written by the indexing model from the issue text.