Bump @testing-library/dom from 6.12.2 to 6.15.0

Bumps [@testing-library/dom](https://github.com/testing-library/dom-testing-library) from 6.12.2 to 6.15.0.
- [Release notes](https://github.com/testing-library/dom-testing-library/releases)
- [Changelog](https://github.com/testing-library/dom-testing-library/blob/master/CHANGELOG.md)
- [Commits](testing-library/dom-testing-library@v6.12.2...v6.15.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>