Bump apps/discourse from `2f60309` to `b21f740`
Bump apps/discourse from `2f60309` to `b21f740`

Bumps [apps/discourse](https://github.com/discourse/discourse) from `2f60309` to `b21f740`.
- [Release notes](https://github.com/discourse/discourse/releases)
- [Commits](https://github.com/discourse/discourse/compare/2f60309b13c5808ee5d8389eaf7e2d9aeb191dcf...b21f74060e865d809ba466cb52e6cb95c7b0cf1f)

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