build(deps): bump org.http4k:http4k-bom from 5.20.0.0 to 5.21.0.0 (#212)

Bumps [org.http4k:http4k-bom](https://github.com/http4k/http4k) from 5.20.0.0 to 5.21.0.0.
- [Release notes](https://github.com/http4k/http4k/releases)
- [Changelog](https://github.com/http4k/http4k/blob/master/CHANGELOG.md)
- [Commits](http4k/http4k@5.20.0.0...5.21.0.0)

---
updated-dependencies:
- dependency-name: org.http4k:http4k-bom
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -42,7 +42,7 @@
 		<kotlin.version>2.0.0</kotlin.version>
 		<kotlin.coroutine.version>1.8.1</kotlin.coroutine.version>
 
-		<http4k.version>5.20.0.0</http4k.version>
+		<http4k.version>5.21.0.0</http4k.version>
 	</properties>
 
 	<dependencies>