Merge pull request #7428 from TechEmpower/dependabot/maven/frameworks/Java/spark/mysql-mysql-connector-java-8.0.28

Bump mysql-connector-java from 8.0.18 to 8.0.28 in /frameworks/Java/spark

frameworks/Java/spark/pom.xml

@@ -15,7 +15,7 @@
         <spark-version>2.9.0</spark-version>
         <hibernate-version>5.4.24.Final</hibernate-version>
         <gson-version>2.8.9</gson-version>
-        <mysql-connector-version>8.0.18</mysql-connector-version>
+        <mysql-connector-version>8.0.28</mysql-connector-version>
         <slf4j-version>1.7.25</slf4j-version>
         <exec.mainClass>hello.web.SparkApplication</exec.mainClass>
     </properties>