Bump org.postgresql:postgresql from 42.6.0 to 42.7.0 in /apps/backend

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] <[email protected]>

apps/backend/pom.xml

@@ -27,7 +27,7 @@
         <commons-collections4.version>4.4</commons-collections4.version>
         <microsoft-graph.version>5.77.0</microsoft-graph.version>
         <msal4j.version>1.14.0</msal4j.version>
-        <postgresql.version>42.6.0</postgresql.version>
+        <postgresql.version>42.7.0</postgresql.version>
 
         <!-- transitive versions -->
         <checker-qual.version>3.40.0</checker-qual.version>