Bump wyrihaximus/async-test-utilities from 4.1.0 to 4.2.1

Bumps [wyrihaximus/async-test-utilities](https://github.com/WyriHaximus/php-async-test-utilities) from 4.1.0 to 4.2.1.
- [Release notes](https://github.com/WyriHaximus/php-async-test-utilities/releases)
- [Commits](WyriHaximus/php-async-test-utilities@4.1.0...4.2.1)

---
updated-dependencies:
- dependency-name: wyrihaximus/async-test-utilities
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]