Bump apps/whitehall from `45f0368` to `789db6e`
Bump apps/whitehall from `45f0368` to `789db6e`

Bumps [apps/whitehall](https://github.com/alphagov/whitehall) from `45f0368` to `789db6e`.
- [Release notes](https://github.com/alphagov/whitehall/releases)
- [Commits](https://github.com/alphagov/whitehall/compare/45f03681d65c6e157c2fc2d7b79b5beb330d724d...789db6e20095aff809e73c752c49b6bb24f2c736)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
eliotsykes/real-world-rails