Bump apps/mastodon from `5d9acc0` to `939a473`
Bump apps/mastodon from `5d9acc0` to `939a473`

Bumps [apps/mastodon](https://github.com/tootsuite/mastodon) from `5d9acc0` to `939a473`.
- [Release notes](https://github.com/tootsuite/mastodon/releases)
- [Commits](https://github.com/tootsuite/mastodon/compare/5d9acc0ce41aa0274fef2dd321a8fad1fb0665ea...939a47393cf7b65bca9fa7817fcc2dbae770cb9c)

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