Bump com.zaxxer:HikariCP from 5.1.0 to 6.0.0 in /service

Bumps [com.zaxxer:HikariCP](https://github.com/brettwooldridge/HikariCP) from 5.1.0 to 6.0.0.
- [Changelog](https://github.com/brettwooldridge/HikariCP/blob/dev/CHANGES)
- [Commits](brettwooldridge/HikariCP@HikariCP-5.1.0...HikariCP-6.0.0)

---
updated-dependencies:
- dependency-name: com.zaxxer:HikariCP
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

service/evaka-bom/build.gradle.kts

@@ -20,7 +20,7 @@ dependencies {
         api(libs.fuel.jackson)
         api("com.google.guava:guava:33.3.0-jre")
         api("com.networknt:json-schema-validator:1.5.0")
-        api("com.zaxxer:HikariCP:5.1.0")
+        api("com.zaxxer:HikariCP:6.0.0")
         api("io.github.microutils:kotlin-logging-jvm:3.0.5")
         api("jakarta.annotation:jakarta.annotation-api:3.0.0")
         api("jakarta.jws:jakarta.jws-api:3.0.0")