Bump org.flywaydb:flyway-core from 9.20.1 to 9.21.0

Bumps [org.flywaydb:flyway-core](https://github.com/flyway/flyway) from 9.20.1 to 9.21.0.
- [Release notes](https://github.com/flyway/flyway/releases)
- [Commits](flyway/flyway@flyway-9.20.1...flyway-9.21.0)

---
updated-dependencies:
- dependency-name: org.flywaydb:flyway-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

build.gradle.kts

@@ -17,7 +17,7 @@ val kithHodemeldingVersion = "1.0.4"
 val jacksonVersion = "2.15.2"
 val mockkVersion = "1.13.5"
 val postgresVersion = "42.6.0"
-val flywayVersion = "9.20.1"
+val flywayVersion = "9.21.0"
 val hikariVersion = "5.0.1"
 val javaTimeAdapterVersion = "1.1.3"
 val kotestVersion = "5.6.2"