⬆️ Bump org.flywaydb:flyway-core in /backend

Bumps [org.flywaydb:flyway-core](https://github.com/flyway/flyway) from 10.17.3 to 10.18.0.
- [Release notes](https://github.com/flyway/flyway/releases)
- [Commits](flyway/flyway@flyway-10.17.3...flyway-10.18.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

backend/build.gradle.kts

@@ -34,7 +34,7 @@ dependencies {
 
     implementation("org.jetbrains.kotlin:kotlin-reflect:2.0.20")
     implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.17.2")
-    implementation("org.flywaydb:flyway-core:10.17.3")
+    implementation("org.flywaydb:flyway-core:10.18.0")
     implementation("org.flywaydb:flyway-database-postgresql:10.18.0")
     implementation("com.github.ben-manes.caffeine:caffeine:3.1.8")
     implementation("io.jsonwebtoken:jjwt-api:0.12.6")