[FLINK-35059] Bump org.postgresql:postgresql to 42.7.3 in flink-connector-jdbc

Bumps [org.postgresql:postgresql](https://github.com/pgjdbc/pgjdbc) from 42.5.1 to 42.5.5.
- [Release notes](https://github.com/pgjdbc/pgjdbc/releases)
- [Changelog](https://github.com/pgjdbc/pgjdbc/blob/master/CHANGELOG.md)
- [Commits](pgjdbc/pgjdbc@REL42.5.1...REL42.5.5)

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

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

Author: dependabot[bot]

flink-connector-jdbc/pom.xml

@@ -38,7 +38,7 @@ under the License.
 		<scala.binary.version>2.12</scala.binary.version>
 		<scala-library.version>2.12.7</scala-library.version>
 		<assertj.version>3.23.1</assertj.version>
-		<postgres.version>42.5.1</postgres.version>
+		<postgres.version>42.7.3</postgres.version>
 		<oracle.version>21.8.0.0</oracle.version>
 		<trino.version>418</trino.version>
 		<byte-buddy.version>1.12.10</byte-buddy.version>