build(deps): bump mysql:mysql-connector-java in /java/springboot

Bumps [mysql:mysql-connector-java](https://github.com/mysql/mysql-connector-j) from 8.0.25 to 8.0.28.
- [Changelog](https://github.com/mysql/mysql-connector-j/blob/release/9.x/CHANGES)
- [Commits](mysql/mysql-connector-j@8.0.25...8.0.28)

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

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

java/springboot/pom.xml

@@ -35,7 +35,7 @@
       <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
-        <version>8.0.25</version>
+        <version>8.0.28</version>
       </dependency>
     <dependency>
       <groupId>org.springframework.boot</groupId>