Bump postgresql from 42.2.17 to 42.2.18 (#7027)

Bumps [postgresql](https://github.com/pgjdbc/pgjdbc) from 42.2.17 to 42.2.18.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/REL42.2.18/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.2.17...REL42.2.18)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

build.gradle

@@ -143,7 +143,7 @@ dependencies {
 
     implementation group: 'org.mariadb.jdbc', name: 'mariadb-java-client', version: '2.7.0'
 
-    implementation 'org.postgresql:postgresql:42.2.17'
+    implementation 'org.postgresql:postgresql:42.2.18'
 
     implementation ('com.oracle.ojdbc:ojdbc10:19.3.0.0') {
         // causing module issues