Bump react and react-dom in /flowauth/frontend

Bumps [react](https://github.com/facebook/react/tree/HEAD/packages/react) and [react-dom](https://github.com/facebook/react/tree/HEAD/packages/react-dom). These dependencies needed to be updated together.

Updates `react` from 17.0.2 to 19.0.0
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v19.0.0/packages/react)

Updates `react-dom` from 17.0.2 to 19.0.0
- [Release notes](https://github.com/facebook/react/releases)
- [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md)
- [Commits](https://github.com/facebook/react/commits/v19.0.0/packages/react-dom)

---
updated-dependencies:
- dependency-name: react
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: react-dom
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]