Bump mysql-connector-java in /frameworks/Java/light-java

Bumps [mysql-connector-java](https://github.com/mysql/mysql-connector-j) from 8.0.18 to 8.0.28.
- [Release notes](https://github.com/mysql/mysql-connector-j/releases)
- [Changelog](https://github.com/mysql/mysql-connector-j/blob/release/8.0/CHANGES)
- [Commits](https://github.com/mysql/mysql-connector-j/compare/8.0.18...8.0.28)

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

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

frameworks/Java/light-java/pom.xml

@@ -27,7 +27,7 @@
         <version.logback>1.2.3</version.logback>
         <version.undertow>2.2.11.Final</version.undertow>
         <version.hikaricp>3.3.1</version.hikaricp>
-        <version.mysql>8.0.18</version.mysql>
+        <version.mysql>8.0.28</version.mysql>
         <version.postgres>42.3.3</version.postgres>
         <version.dsl-json>1.8.4</version.dsl-json>
         <version.mustache>0.9.6</version.mustache>