chore(java): Bump org.postgresql:postgresql from 42.7.8 to 42.7.9 in /java (#3901)

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from
42.7.8 to 42.7.9.

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

Author: dependabot[bot]

java/driver/jdbc-validation-postgresql/pom.xml

@@ -50,7 +50,7 @@
     <dependency>
       <groupId>org.postgresql</groupId>
       <artifactId>postgresql</artifactId>
-      <version>42.7.8</version>
+      <version>42.7.9</version>
       <scope>test</scope>
     </dependency>