Bump org.postgresql:postgresql from 42.6.0 to 42.7.0 in /kotlin

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from 42.6.0 to 42.7.0.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.6.0...REL42.7.0)

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

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

kotlin/gradle/libs.versions.toml

@@ -21,7 +21,7 @@
 # Define version we can use as version.ref in [plugins] and [libraries], see flyway-core example below
 # CAUTION: 9.22.3 leads to Caused by: java.lang.IllegalArgumentException: Unsupported class file major v 63 (Java 19)
 flyway = "9.21.1"
-postgresql="42.6.0"
+postgresql="42.7.0"
 
 # plugins Were added in Gradle 7.2, are used (obviouly) to define plugins.
 [plugins]