chore(deps): bump org.postgresql:postgresql from 42.5.4 to 42.6.0

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from 42.5.4 to 42.6.0.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.5.4...REL42.6.0)

---
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>

plugin-jdbc-postgres/build.gradle

@@ -1,5 +1,5 @@
 dependencies {
-    jdbcDriver 'org.postgresql:postgresql:42.5.4'
+    jdbcDriver 'org.postgresql:postgresql:42.6.0'
     implementation project(':plugin-jdbc')
     api 'org.bouncycastle:bcprov-jdk15on:1.70'
     api 'org.bouncycastle:bcpkix-jdk15on:1.70'