Bump org.postgresql:postgresql from 42.3.8 to 42.3.9

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from 42.3.8 to 42.3.9.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.3.8...REL42.3.9)

---
updated-dependencies:
- dependency-name: org.postgresql:postgresql
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

pom.xml

@@ -177,7 +177,7 @@
     <mybatis-plus.version>3.4.3.4</mybatis-plus.version>
     <mysql.connector.version>8.0.28</mysql.connector.version>
     <mysql.connector.scope>test</mysql.connector.scope>
-    <postgresql.connector.version>42.3.8</postgresql.connector.version>
+    <postgresql.connector.version>42.3.9</postgresql.connector.version>
     <druid.version>1.2.16</druid.version>
     <mongodb.driver.version>3.12.8</mongodb.driver.version>