fix: handle errors thrown in fixtures

[dsyddall]

Description

Fixes #4435

When running a test with a fixture function that throws an error, the error is not handled by the test runner and the test times out. (Reproduction: https://stackblitz.com/edit/vitest-dev-vitest-72lr7i?file=test%2Ffixture-error.test.ts)

Example:

import { test } from 'vitest';

const myTest = test.extend<{ a: never }>({
  a: async () => {
    throw new Error('Error thrown in test fixture');
  },
});

myTest('error in fixture causes a timeout', ({ a }) => {});

Instead of timing out, the test runner should handle the error immediately. This PR amends the withFixtures function to catch any rejected fixture promise and forwards the error so that the test fails immediately.

Please don't delete this checklist! Before submitting the PR, please make sure you do the following:

• It's really useful if your PR references an issue where it is discussed ahead of time. If the feature is substantial or introduces breaking changes without a discussion, PR might be closed.
• Ideally, include a test that fails without this PR but passes with it.
• Please, don't make changes to pnpm-lock.yaml unless you introduce a new test example.

Tests

• Run the tests with pnpm test:ci.

Documentation

• If you introduce new functionality, document it. You can run documentation with pnpm run docs command.

Changesets

• Changes in changelog are generated from PR name. Please, make sure that it explains your changes in an understandable manner. Please, prefix changeset messages with feat:, fix:, perf:, docs:, or chore:.

[stackblitz]

Run & review this pull request in StackBlitz Codeflow.

[netlify]

✅ Deploy Preview for fastidious-cascaron-4ded94 canceled.

Name	Link
🔨 Latest commit	6c7e972
🔍 Latest deploy log	https://app.netlify.com/sites/fastidious-cascaron-4ded94/deploys/654538c18f05af000848ec9f