Bump mysql-connector-java from 8.0.16 to 8.0.28

Bumps [mysql-connector-java](https://github.com/mysql/mysql-connector-j) from 8.0.16 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](mysql/mysql-connector-j@8.0.16...8.0.28)

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

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

pom.xml

@@ -19,7 +19,7 @@
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <java.version>1.8</java.version>
         <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
-        <mysql.version>8.0.16</mysql.version>
+        <mysql.version>8.0.28</mysql.version>
         <h2.version>2.1.210</h2.version>
         <druid.version>1.1.9</druid.version>
         <quartz.version>2.3.2</quartz.version>