Bump apps/whitehall from `b944c5d` to `88174f9`
Bump apps/whitehall from `b944c5d` to `88174f9`

Bumps [apps/whitehall](https://github.com/alphagov/whitehall) from `b944c5d` to `88174f9`.
- [Release notes](https://github.com/alphagov/whitehall/releases)
- [Commits](https://github.com/alphagov/whitehall/compare/b944c5d91a67a1e274f873ca62da7be0d34f1c9c...88174f986963ca08fe856e45333becda2c56fce9)

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