Bump mysql:mysql-connector-java in /openidm-repo-jdbc

Bumps [mysql:mysql-connector-java](https://github.com/mysql/mysql-connector-j) from 5.1.25 to 8.0.28.
- [Changelog](https://github.com/mysql/mysql-connector-j/blob/release/8.x/CHANGES)
- [Commits](mysql/mysql-connector-j@5.1.25...8.0.28)

---
updated-dependencies:
- dependency-name: mysql:mysql-connector-java
  dependency-type: direct:development
...

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

openidm-repo-jdbc/pom.xml

@@ -129,7 +129,7 @@
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
-            <version>5.1.25</version>
+            <version>8.0.28</version>
             <scope>test</scope>
         </dependency>
         <dependency>